报错 error C2664: 'CreateWindowExA' : cannot convert parameter 2 from 'unsigned short [10]' to 'const char *'

最新推荐文章于 2021-05-26 16:14:12 发布
原创 最新推荐文章于 2021-05-26 16:14:12 发布 · 5.3k 阅读 · 0 ·
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#c #null

本文介绍了解决在使用CreateWindow函数时遇到的参数类型不匹配错误的具体方法。通过调整字符串前缀，使得代码能够在不同编译环境中正确运行。

    //创建窗口
    HWND hWnd = CreateWindow( L"ClassName", "三维字体",
                              WS_OVERLAPPEDWINDOW, 200, 100, 600,500,
                              GetDesktopWindow(), NULL, wc.hInstance, NULL );

报错

 error C2664: 'CreateWindowExA' : cannot convert parameter 2 from 'unsigned short [10]' to 'const char *'

 

因为这段代码是在 vs2005写的 在vc6

去掉“L”

    //创建窗口
    HWND hWnd = CreateWindow( "ClassName", "三维字体",
                              WS_OVERLAPPEDWINDOW, 200, 100, 600,500,
                              GetDesktopWindow(), NULL, wc.hInstance, NULL );

MFC之调用DLL的问题：error C2664: “LoadLibraryW”: 不能将参数 1 从“const char *”转换为“LPCWSTR
xk_snail的专栏
07-04 4951
今天在项目中遇到了一个小小的问题，在调用别人动态连接库（DLL）的时候，总是出现如下提示，导致程序无法正常运行，编程环境：VS2010+MFC 问题提示：error C2664: “LoadLibraryW”: 不能将参数 1 从“const char *”转换为“LPCWSTR 经过查找资料，问题得以解决，感谢： 解决方法来源于：http://blog.sina.com.cn/s/blog
报错 error C2664: 'CreateWindowExA' : cannot convert parameter 2 from 'unsigned short [10]' to 'const ...
weixin_30894583的博客
01-03 295
//创建窗口 HWND hWnd = CreateWindow( L"ClassName", "三维字体", WS_OVERLAPPEDWINDOW, 200, 100, 600,500, GetDesktopWindow(), NULL, wc.hInstance, ...
c语言c2664printf,C语言 error C2664: 'strcmp' : cannot convert parameter 1 from 'char' to 'const char *'错...
weixin_39732640的博客
05-26 3352
1.你要注意了，如果你纯粹读入一个字符就应该用getchar()函数而不是scanf()，这是个习惯问题。因为如果你需要输入空格符时候scanf会认为空格用于隔开各部分数据而把空格忽略。2.strcmp函数适用于比较字符串的，例如strcmp("hello","equal");或者是：char *s1="hello",*s2="equal";strcmp(s1,s2);你的错误就是因为你比较单个字...
error C2664: 'MessageBoxW' : cannot convert parameter 2 from
lvcayu的专栏
09-19 1609
error C2664: 'MessageBoxW' <br />有一个项目，开始的时候可以正常运行，在重装系统以及重装VC之后，出现下面的错误，<br />error C2664: 'MessageBoxW' : cannot convert parameter 2 from ......<br />在优快云中找到了解决的办法：<br />MessageBox(NULL,"hello","msg",MB_OK)编译不过去，要改成MessageBox(NULL,TEXT("hello"),TEXT("ms
error C2664:cannot convert parameter 2 from 'char [260]' to 'LPWCH'
huxincheng87的专栏
07-30 1748
编译环境：Windows XP + VS2008 在VC6中可以编译成功的代码在VS2005，VS2008中编译出错。 原因：LPWCH是指long pointer to wide char，VS2005和2008默认使用unicode编码，而vc6默认使用多字节编码。 解决方法： （1）将char改为wchar_t，但是会引起很多问题（在既有代码中） （2）在项目的
||=== Build: Debug in 作业 (compiler: GNU GCC Compiler) ===| D:\作业\main.cpp|20|error: 'getFirst' declared as function returning a function| D:\作业\main.cpp|24|error: 'getSecond' declared as function returning a function| D:\作业\main.cpp||In function 'int main()':| D:\作业\main.cpp|33|error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'const char [2]')| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|168|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|168|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: cannot bind non-const lvalue reference of type 'bool&' to an rvalue of type 'bool'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|172|note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|172|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'short int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(short int)((const char*)"(")' to 'short int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|175|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|175|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'short unsigned int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(short unsigned int)((const char*)"(")' to 'short unsigned int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|179|note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|179|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(int)((const char*)"(")' to 'int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|182|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|182|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'unsigned int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(unsigned int)((const char*)"(")' to 'unsigned int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|186|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|186|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'long int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(long int)((const char*)"(")' to 'long int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|190|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|190|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'long unsigned int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(long unsigned int)((const char*)"(")' to 'long unsigned int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|195|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|195|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'long long int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(long long int)((const char*)"(")' to 'long long int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|199|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|199|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const char*' to 'long long unsigned int' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(long long unsigned int)((const char*)"(")' to 'long long unsigned int&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|235|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]' <near match>| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|235|note: conversion of argument 1 would be ill-formed:| D:\作业\main.cpp|33|error: invalid conversion from 'const void*' to 'void*' [-fpermissive]| D:\作业\main.cpp|33|error: cannot bind rvalue '(void*)((const void*)((const char*)"("))' to 'void*&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|120|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|120|note: no known conversion for argument 1 from 'const char [2]' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'}| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|124|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|124|note: no known conversion for argument 1 from 'const char [2]' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|131|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|131|note: no known conversion for argument 1 from 'const char [2]' to 'std::ios_base& (*)(std::ios_base&)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|214|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|214|note: no known conversion for argument 1 from 'const char [2]' to 'float&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|218|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|218|note: no known conversion for argument 1 from 'const char [2]' to 'double&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|222|note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|222|note: no known conversion for argument 1 from 'const char [2]' to 'long double&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|259|note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|259|note: no known conversion for argument 1 from 'const char [2]' to 'std::basic_istream<char>::__streambuf_type*' {aka 'std::basic_streambuf<char>*'}| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\bits\basic_string.tcc|1465|note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\bits\basic_string.tcc|1465|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'const char [2]'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\bits\istream.tcc|931|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\bits\istream.tcc|931|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: deduced conflicting types for parameter '_CharT' ('char' and 'const char [2]')| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|756|note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|756|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'unsigned char&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|761|note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|761|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'signed char&'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\bits\istream.tcc|963|note: candidate: 'template<class _CharT2, class _Traits2> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT2*)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\bits\istream.tcc|963|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: deduced conflicting types for parameter '_CharT2' ('char' and 'const char')| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|803|note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|803|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'unsigned char*'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|808|note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|808|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'signed char*'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|980|note: candidate: 'template<class _Istream, class _Tp> typename std::enable_if<std::__and_<std::__not_<std::is_lvalue_reference<_Tp> >, std::__is_convertible_to_basic_istream<_Istream>, std::__is_extractable<typename std::__is_convertible_to_basic_istream<_Tp>::__istream_type, _Tp&&, void> >::value, typename std::__is_convertible_to_basic_istream<_Tp>::__istream_type>::type std::operator>>(_Istream&&, _Tp&&)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|980|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|required from here| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\istream|980|error: no type named 'type' in 'struct std::enable_if<false, std::basic_istream<char>&>'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|71|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Resetiosflags)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|71|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'std::_Resetiosflags'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|101|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setiosflags)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|101|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'std::_Setiosflags'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|132|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setbase)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|132|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'std::_Setbase'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|170|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setfill<_CharT>)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|170|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: mismatched types 'std::_Setfill<_CharT>' and 'const char*'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|200|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setprecision)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|200|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'std::_Setprecision'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|230|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setw)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|230|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: cannot convert '"("' (type 'const char [2]') to type 'std::_Setw'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|264|note: candidate: 'template<class _CharT, class _Traits, class _MoneyT> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Get_money<_MoneyT>)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|264|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: mismatched types 'std::_Get_money<_MoneyT>' and 'const char*'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|418|note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Get_time<_CharT>)'| C:\Program Files\CodeBlocks\MinGW\lib\gcc\x86_64-w64-mingw32\8.1.0\include\c++\iomanip|418|note: template argument deduction/substitution failed:| D:\作业\main.cpp|33|note: mismatched types 'std::_Get_time<_CharT>' and 'const char*'| D:\作业\main.cpp|34|error: missing template arguments before 'p'| D:\作业\main.cpp|35|error: 'p' was not declared in this scope| ||=== Build failed: 25 error(s), 1 warning(s) (0 minute(s), 0 second(s)) ===|
06-10
如果必须使用 `const char[]`，则需要通过其他方式处理输入数据，例如先读取到可修改的变量中再进行转换[^2]。 #### 示例代码 以下是一个综合示例，展示如何正确声明函数并处理输入操作符问题： ```cpp #include ...
a.cpp: In function ‘int main()’: a.cpp:9:9: error: no match for ‘operator>>’ (operand types are ‘std::istream’ {aka ‘std::basic_istream<char>’} and ‘char*’) 9 | cin >> (s + 1); | ~~~ ^~ ~~~~~~~ | | | | | char* | std::istream {aka std::basic_istream<char>} In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:168:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 168 | operator>>(bool& __n) | ^~~~~~~~ /usr/include/c++/11/istream:168:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: cannot bind non-const lvalue reference of type ‘bool&’ to a value of type ‘char*’ 9 | cin >> (s + 1); | ~~~^~~~ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:172:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]’ (near match) 172 | operator>>(short& __n); | ^~~~~~~~ /usr/include/c++/11/istream:172:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘short int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(short int)(((char*)(& s)) + 1)’ to ‘short int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:175:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 175 | operator>>(unsigned short& __n) | ^~~~~~~~ /usr/include/c++/11/istream:175:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘short unsigned int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(short unsigned int)(((char*)(& s)) + 1)’ to ‘short unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:179:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]’ (near match) 179 | operator>>(int& __n); | ^~~~~~~~ /usr/include/c++/11/istream:179:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(int)(((char*)(& s)) + 1)’ to ‘int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:182:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 182 | operator>>(unsigned int& __n) | ^~~~~~~~ /usr/include/c++/11/istream:182:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘unsigned int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(unsigned int)(((char*)(& s)) + 1)’ to ‘unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:186:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 186 | operator>>(long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:186:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘long int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(long int)(((char*)(& s)) + 1)’ to ‘long int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:190:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 190 | operator>>(unsigned long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:190:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘long unsigned int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(long unsigned int)(((char*)(& s)) + 1)’ to ‘long unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:195:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 195 | operator>>(long long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:195:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘long long int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(long long int)(((char*)(& s)) + 1)’ to ‘long long int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:199:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 199 | operator>>(unsigned long long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:199:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: invalid conversion from ‘char*’ to ‘long long unsigned int’ [-fpermissive] 9 | cin >> (s + 1); | ~~~^~~~ | | | char* a.cpp:9:15: error: cannot bind rvalue ‘(long long unsigned int)(((char*)(& s)) + 1)’ to ‘long long unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:235:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 235 | operator>>(void*& __p) | ^~~~~~~~ /usr/include/c++/11/istream:235:7: note: conversion of argument 1 would be ill-formed: a.cpp:9:15: error: cannot bind non-const lvalue reference of type ‘void*&’ to an rvalue of type ‘void*’ 9 | cin >> (s + 1); | ~~~^~~~ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:120:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 120 | operator>>(__istream_type& (*__pf)(__istream_type&)) | ^~~~~~~~ /usr/include/c++/11/istream:120:36: note: no known conversion for argument 1 from ‘char*’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)’ {aka ‘std::basic_istream<char>& (*)(std::basic_istream<char>&)’} 120 | operator>>(__istream_type& (*__pf)(__istream_type&)) | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/istream:124:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]’ 124 | operator>>(__ios_type& (*__pf)(__ios_type&)) | ^~~~~~~~ /usr/include/c++/11/istream:124:32: note: no known conversion for argument 1 from ‘char*’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)’ {aka ‘std::basic_ios<char>& (*)(std::basic_ios<char>&)’} 124 | operator>>(__ios_type& (*__pf)(__ios_type&)) | ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~ /usr/include/c++/11/istream:131:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 131 | operator>>(ios_base& (*__pf)(ios_base&)) | ^~~~~~~~ /usr/include/c++/11/istream:131:30: note: no known conversion for argument 1 from ‘char*’ to ‘std::ios_base& (*)(std::ios_base&)’ 131 | operator>>(ios_base& (*__pf)(ios_base&)) | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~ /usr/include/c++/11/istream:214:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 214 | operator>>(float& __f) | ^~~~~~~~ /usr/include/c++/11/istream:214:25: note: no known conversion for argument 1 from ‘char*’ to ‘float&’ 214 | operator>>(float& __f) | ~~~~~~~^~~ /usr/include/c++/11/istream:218:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 218 | operator>>(double& __f) | ^~~~~~~~ /usr/include/c++/11/istream:218:26: note: no known conversion for argument 1 from ‘char*’ to ‘double&’ 218 | operator>>(double& __f) | ~~~~~~~~^~~ /usr/include/c++/11/istream:222:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 222 | operator>>(long double& __f) | ^~~~~~~~ /usr/include/c++/11/istream:222:31: note: no known conversion for argument 1 from ‘char*’ to ‘long double&’ 222 | operator>>(long double& __f) | ~~~~~~~~~~~~~^~~ /usr/include/c++/11/istream:259:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]’ 259 | operator>>(__streambuf_type* __sb); | ^~~~~~~~ /usr/include/c++/11/istream:259:36: note: no known conversion for argument 1 from ‘char*’ to ‘std::basic_istream<char>::__streambuf_type*’ {aka ‘std::basic_streambuf<char>*’} 259 | operator>>(__streambuf_type* __sb); | ~~~~~~~~~~~~~~~~~~^~~~ In file included from /usr/include/c++/11/string:56, from /usr/include/c++/11/bits/locale_classes.h:40, from /usr/include/c++/11/bits/ios_base.h:41, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/basic_string.tcc:1485:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)’ 1485 | operator>>(basic_istream<_CharT, _Traits>& __in, | ^~~~~~~~ /usr/include/c++/11/bits/basic_string.tcc:1485:5: note: template argument deduction/substitution failed: a.cpp:9:18: note: mismatched types ‘std::__cxx11::basic_string<_CharT, _Traits, _Allocator>’ and ‘char*’ 9 | cin >> (s + 1); | ^ In file included from /usr/include/c++/11/istream:1016, from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/bits/istream.tcc:958:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&)’ 958 | operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c) | ^~~~~~~~ /usr/include/c++/11/bits/istream.tcc:958:5: note: template argument deduction/substitution failed: a.cpp:9:18: note: deduced conflicting types for parameter ‘_CharT’ (‘char’ and ‘char*’) 9 | cin >> (s + 1); | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:756:5: note: candidate: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)’ 756 | operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c) | ^~~~~~~~ /usr/include/c++/11/istream:756:5: note: template argument deduction/substitution failed: a.cpp:9:15: note: cannot convert ‘(((char*)(& s)) + 1)’ (type ‘char*’) to type ‘unsigned char&’ 9 | cin >> (s + 1); | ~~~^~~~ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:761:5: note: candidate: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)’ 761 | operator>>(basic_istream<char, _Traits>& __in, signed char& __c) | ^~~~~~~~ /usr/include/c++/11/istream:761:5: note: template argument deduction/substitution failed: a.cpp:9:15: note: cannot convert ‘(((char*)(& s)) + 1)’ (type ‘char*’) to type ‘signed char&’ 9 | cin >> (s + 1); | ~~~^~~~ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:859:5: note: candidate: ‘template<class _CharT, class _Traits, long unsigned int _Num> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT (&)[_Num])’ 859 | operator>>(basic_istream<_CharT, _Traits>& __in, _CharT (&__s)[_Num]) | ^~~~~~~~ /usr/include/c++/11/istream:859:5: note: template argument deduction/substitution failed: a.cpp:9:18: note: mismatched types ‘_CharT [_Num]’ and ‘char*’ 9 | cin >> (s + 1); | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:868:5: note: candidate: ‘template<class _Traits, long unsigned int _Num> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char (&)[_Num])’ 868 | operator>>(basic_istream<char, _Traits>& __in, unsigned char (&__s)[_Num]) | ^~~~~~~~ /usr/include/c++/11/istream:868:5: note: template argument deduction/substitution failed: a.cpp:9:18: note: mismatched types ‘unsigned char [_Num]’ and ‘char*’ 9 | cin >> (s + 1); | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:873:5: note: candidate: ‘template<class _Traits, long unsigned int _Num> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char (&)[_Num])’ 873 | operator>>(basic_istream<char, _Traits>& __in, signed char (&__s)[_Num]) | ^~~~~~~~ /usr/include/c++/11/istream:873:5: note: template argument deduction/substitution failed: a.cpp:9:18: note: mismatched types ‘signed char [_Num]’ and ‘char*’ 9 | cin >> (s + 1); | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:1006:5: note: candidate: ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&)’ 1006 | operator>>(_Istream&& __is, _Tp&& __x) | ^~~~~~~~ /usr/include/c++/11/istream:1006:5: note: template argument deduction/substitution failed: /usr/include/c++/11/istream: In substitution of ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&) [with _Istream = std::basic_istream<char>&; _Tp = char*]’: a.cpp:9:18: required from here /usr/include/c++/11/istream:1006:5: error: template constraint failure for ‘template<class _Is, class _Tp> requires (__derived_from_ios_base<_Is>) && requires(_Is& __is, _Tp&& __t) {__is >> (forward<_Tp>)(__t);} using __rvalue_stream_extraction_t = _Is&&’ /usr/include/c++/11/istream:1006:5: note: constraints not satisfied In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream: In substitution of ‘template<class _Is, class _Tp> requires (__derived_from_ios_base<_Is>) && requires(_Is& __is, _Tp&& __t) {__is >> (forward<_Tp>)(__t);} using __rvalue_stream_extraction_t = _Is&& [with _Is = std::basic_istream<char>&; _Tp = char*]’: /usr/include/c++/11/istream:1006:5: required by substitution of ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&) [with _Istream = std::basic_istream<char>&; _Tp = char*]’ a.cpp:9:18: required from here /usr/include/c++/11/ostream:717:13: required for the satisfaction of ‘__derived_from_ios_base<_Is>’ [with _Is = std::basic_istream<char, std::char_traits<char> >&] /usr/include/c++/11/ostream:717:39: note: the expression ‘is_class_v<_Tp> [with _Tp = std::basic_istream<char, std::char_traits<char> >&]’ evaluated to ‘false’ 717 | concept __derived_from_ios_base = is_class_v<_Tp> | ^~~~~~~~~~~~~~~ a.cpp:10:13: error: ‘strlen’ was not declared in this scope 10 | int n = strlen(s + 1); | ^~~~~~ a.cpp:2:1: note: ‘strlen’ is defined in header ‘<cstring>’; did you forget to ‘#include <cstring>’? 1 | #include <iostream> +++ |+#include <cstring> 2 | using namespace std;
最新发布
12-06
在C++代码中，出现 `'no match for ‘operator>>’ (operand types are ‘std::istream’ {aka ‘std::basic_istream<char>’} and ‘char*’)’` 和 `‘strlen’ was not declared in this scope` 错误，通常是由于...
a.cpp: In constructor ‘BigInt::BigInt(std::string)’: a.cpp:9:31: error: expected ‘{’ at end of input 9 | BigInt(string s):number(s);//构造函数 | ^ a.cpp: In function ‘std::istream operator>>(std::istream, BigInt)’: a.cpp:14:16: error: ‘std::basic_istream<_CharT, _Traits>::basic_istream(std::basic_istream<_CharT, _Traits>&&) [with _CharT = char; _Traits = std::char_traits<char>]’ is protected within this context 14 | return in; | ^~ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:613:7: note: declared protected here 613 | basic_istream(basic_istream&& __rhs) | ^~~~~~~~~~~~~ a.cpp: In function ‘std::ostream operator>>(std::ostream, BigInt)’: a.cpp:19:16: error: ‘std::basic_ostream<_CharT, _Traits>::basic_ostream(std::basic_ostream<_CharT, _Traits>&&) [with _CharT = char; _Traits = std::char_traits<char>]’ is protected within this context 19 | return out; | ^~~ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:406:7: note: declared protected here 406 | basic_ostream(basic_ostream&& __rhs) | ^~~~~~~~~~~~~ a.cpp: In function ‘int main()’: a.cpp:46:16: error: no matching function for call to ‘BigInt::BigInt()’ 46 | BigInt a, b, c; | ^ a.cpp:9:5: note: candidate: ‘BigInt::BigInt(std::string)’ 9 | BigInt(string s):number(s);//构造函数 | ^~~~~~ a.cpp:9:5: note: candidate expects 1 argument, 0 provided a.cpp:6:7: note: candidate: ‘BigInt::BigInt(const BigInt&)’ 6 | class BigInt | ^~~~~~ a.cpp:6:7: note: candidate expects 1 argument, 0 provided a.cpp:6:7: note: candidate: ‘BigInt::BigInt(BigInt&&)’ a.cpp:6:7: note: candidate expects 1 argument, 0 provided a.cpp:46:19: error: no matching function for call to ‘BigInt::BigInt()’ 46 | BigInt a, b, c; | ^ a.cpp:9:5: note: candidate: ‘BigInt::BigInt(std::string)’ 9 | BigInt(string s):number(s);//构造函数 | ^~~~~~ a.cpp:9:5: note: candidate expects 1 argument, 0 provided a.cpp:6:7: note: candidate: ‘BigInt::BigInt(const BigInt&)’ 6 | class BigInt | ^~~~~~ a.cpp:6:7: note: candidate expects 1 argument, 0 provided a.cpp:6:7: note: candidate: ‘BigInt::BigInt(BigInt&&)’ a.cpp:6:7: note: candidate expects 1 argument, 0 provided a.cpp:46:22: error: no matching function for call to ‘BigInt::BigInt()’ 46 | BigInt a, b, c; | ^ a.cpp:9:5: note: candidate: ‘BigInt::BigInt(std::string)’ 9 | BigInt(string s):number(s);//构造函数 | ^~~~~~ a.cpp:9:5: note: candidate expects 1 argument, 0 provided a.cpp:6:7: note: candidate: ‘BigInt::BigInt(const BigInt&)’ 6 | class BigInt | ^~~~~~ a.cpp:6:7: note: candidate expects 1 argument, 0 provided a.cpp:6:7: note: candidate: ‘BigInt::BigInt(BigInt&&)’ a.cpp:6:7: note: candidate expects 1 argument, 0 provided a.cpp:47:14: error: use of deleted function ‘std::basic_istream<_CharT, _Traits>::basic_istream(const std::basic_istream<_CharT, _Traits>&) [with _CharT = char; _Traits = std::char_traits<char>]’ 47 | cin>>a>>b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:611:7: note: declared here 611 | basic_istream(const basic_istream&) = delete; | ^~~~~~~~~~~~~ a.cpp:11:39: note: initializing argument 1 of ‘std::istream operator>>(std::istream, BigInt)’ 11 | friend istream operator>>(istream in,BigInt b) | ~~~~~~~~^~ a.cpp:49:13: error: no match for ‘operator<<’ (operand types are ‘std::ostream’ {aka ‘std::basic_ostream<char>’} and ‘BigInt’) 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ~~~~^~~ | | | | | BigInt | std::ostream {aka std::basic_ostream<char>} In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:108:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ostream_type& (*)(std::basic_ostream<_CharT, _Traits>::__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 108 | operator<<(__ostream_type& (*__pf)(__ostream_type&)) | ^~~~~~~~ /usr/include/c++/11/ostream:108:36: note: no known conversion for argument 1 from ‘BigInt’ to ‘std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&)’ {aka ‘std::basic_ostream<char>& (*)(std::basic_ostream<char>&)’} 108 | operator<<(__ostream_type& (*__pf)(__ostream_type&)) | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/ostream:117:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ios_type& (*)(std::basic_ostream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>; std::basic_ostream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]’ 117 | operator<<(__ios_type& (*__pf)(__ios_type&)) | ^~~~~~~~ /usr/include/c++/11/ostream:117:32: note: no known conversion for argument 1 from ‘BigInt’ to ‘std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&)’ {aka ‘std::basic_ios<char>& (*)(std::basic_ios<char>&)’} 117 | operator<<(__ios_type& (*__pf)(__ios_type&)) | ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~ /usr/include/c++/11/ostream:127:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 127 | operator<<(ios_base& (*__pf) (ios_base&)) | ^~~~~~~~ /usr/include/c++/11/ostream:127:30: note: no known conversion for argument 1 from ‘BigInt’ to ‘std::ios_base& (*)(std::ios_base&)’ 127 | operator<<(ios_base& (*__pf) (ios_base&)) | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ /usr/include/c++/11/ostream:166:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 166 | operator<<(long __n) | ^~~~~~~~ /usr/include/c++/11/ostream:166:23: note: no known conversion for argument 1 from ‘BigInt’ to ‘long int’ 166 | operator<<(long __n) | ~~~~~^~~ /usr/include/c++/11/ostream:170:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 170 | operator<<(unsigned long __n) | ^~~~~~~~ /usr/include/c++/11/ostream:170:32: note: no known conversion for argument 1 from ‘BigInt’ to ‘long unsigned int’ 170 | operator<<(unsigned long __n) | ~~~~~~~~~~~~~~^~~ /usr/include/c++/11/ostream:174:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 174 | operator<<(bool __n) | ^~~~~~~~ /usr/include/c++/11/ostream:174:23: note: no known conversion for argument 1 from ‘BigInt’ to ‘bool’ 174 | operator<<(bool __n) | ~~~~~^~~ In file included from /usr/include/c++/11/ostream:829, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/ostream.tcc:91:5: note: candidate: ‘std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char; _Traits = std::char_traits<char>]’ 91 | basic_ostream<_CharT, _Traits>:: | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/bits/ostream.tcc:92:22: note: no known conversion for argument 1 from ‘BigInt’ to ‘short int’ 92 | operator<<(short __n) | ~~~~~~^~~ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:181:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 181 | operator<<(unsigned short __n) | ^~~~~~~~ /usr/include/c++/11/ostream:181:33: note: no known conversion for argument 1 from ‘BigInt’ to ‘short unsigned int’ 181 | operator<<(unsigned short __n) | ~~~~~~~~~~~~~~~^~~ In file included from /usr/include/c++/11/ostream:829, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/ostream.tcc:105:5: note: candidate: ‘std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char; _Traits = std::char_traits<char>]’ 105 | basic_ostream<_CharT, _Traits>:: | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/bits/ostream.tcc:106:20: note: no known conversion for argument 1 from ‘BigInt’ to ‘int’ 106 | operator<<(int __n) | ~~~~^~~ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:192:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 192 | operator<<(unsigned int __n) | ^~~~~~~~ /usr/include/c++/11/ostream:192:31: note: no known conversion for argument 1 from ‘BigInt’ to ‘unsigned int’ 192 | operator<<(unsigned int __n) | ~~~~~~~~~~~~~^~~ /usr/include/c++/11/ostream:201:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 201 | operator<<(long long __n) | ^~~~~~~~ /usr/include/c++/11/ostream:201:28: note: no known conversion for argument 1 from ‘BigInt’ to ‘long long int’ 201 | operator<<(long long __n) | ~~~~~~~~~~^~~ /usr/include/c++/11/ostream:205:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 205 | operator<<(unsigned long long __n) | ^~~~~~~~ /usr/include/c++/11/ostream:205:37: note: no known conversion for argument 1 from ‘BigInt’ to ‘long long unsigned int’ 205 | operator<<(unsigned long long __n) | ~~~~~~~~~~~~~~~~~~~^~~ /usr/include/c++/11/ostream:220:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 220 | operator<<(double __f) | ^~~~~~~~ /usr/include/c++/11/ostream:220:25: note: no known conversion for argument 1 from ‘BigInt’ to ‘double’ 220 | operator<<(double __f) | ~~~~~~~^~~ /usr/include/c++/11/ostream:224:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(float) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 224 | operator<<(float __f) | ^~~~~~~~ /usr/include/c++/11/ostream:224:24: note: no known conversion for argument 1 from ‘BigInt’ to ‘float’ 224 | operator<<(float __f) | ~~~~~~^~~ /usr/include/c++/11/ostream:232:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long double) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 232 | operator<<(long double __f) | ^~~~~~~~ /usr/include/c++/11/ostream:232:30: note: no known conversion for argument 1 from ‘BigInt’ to ‘long double’ 232 | operator<<(long double __f) | ~~~~~~~~~~~~^~~ /usr/include/c++/11/ostream:245:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(const void*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]’ 245 | operator<<(const void* __p) | ^~~~~~~~ /usr/include/c++/11/ostream:245:30: note: no known conversion for argument 1 from ‘BigInt’ to ‘const void*’ 245 | operator<<(const void* __p) | ~~~~~~~~~~~~^~~ /usr/include/c++/11/ostream:250:7: note: candidate: ‘std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::nullptr_t) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>; std::nullptr_t = std::nullptr_t]’ 250 | operator<<(nullptr_t) | ^~~~~~~~ /usr/include/c++/11/ostream:250:18: note: no known conversion for argument 1 from ‘BigInt’ to ‘std::nullptr_t’ 250 | operator<<(nullptr_t) | ^~~~~~~~~ In file included from /usr/include/c++/11/ostream:829, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/ostream.tcc:119:5: note: candidate: ‘std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]’ 119 | basic_ostream<_CharT, _Traits>:: | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/bits/ostream.tcc:120:34: note: no known conversion for argument 1 from ‘BigInt’ to ‘std::basic_ostream<char>::__streambuf_type*’ {aka ‘std::basic_streambuf<char>*’} 120 | operator<<(__streambuf_type* __sbin) | ~~~~~~~~~~~~~~~~~~^~~~~~ In file included from /usr/include/c++/11/bits/basic_string.h:48, from /usr/include/c++/11/string:55, from /usr/include/c++/11/bits/locale_classes.h:40, from /usr/include/c++/11/bits/ios_base.h:41, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/string_view:667:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, std::basic_string_view<_CharT, _Traits>)’ 667 | operator<<(basic_ostream<_CharT, _Traits>& __os, | ^~~~~~~~ /usr/include/c++/11/string_view:667:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: ‘BigInt’ is not derived from ‘std::basic_string_view<_CharT, _Traits>’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/string:55, from /usr/include/c++/11/bits/locale_classes.h:40, from /usr/include/c++/11/bits/ios_base.h:41, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/basic_string.h:6531:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)’ 6531 | operator<<(basic_ostream<_CharT, _Traits>& __os, | ^~~~~~~~ /usr/include/c++/11/bits/basic_string.h:6531:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: ‘BigInt’ is not derived from ‘const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/bits/ios_base.h:46, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/system_error:279:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::error_code&)’ 279 | operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e) | ^~~~~~~~ /usr/include/c++/11/system_error:279:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const std::error_code&’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:513:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, _CharT)’ 513 | operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c) | ^~~~~~~~ /usr/include/c++/11/ostream:513:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: deduced conflicting types for parameter ‘_CharT’ (‘char’ and ‘BigInt’) 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:518:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, char)’ 518 | operator<<(basic_ostream<_CharT, _Traits>& __out, char __c) | ^~~~~~~~ /usr/include/c++/11/ostream:518:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:524:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char)’ 524 | operator<<(basic_ostream<char, _Traits>& __out, char __c) | ^~~~~~~~ /usr/include/c++/11/ostream:524:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:530:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, signed char)’ 530 | operator<<(basic_ostream<char, _Traits>& __out, signed char __c) | ^~~~~~~~ /usr/include/c++/11/ostream:530:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘signed char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:535:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, unsigned char)’ 535 | operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c) | ^~~~~~~~ /usr/include/c++/11/ostream:535:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘unsigned char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:544:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, wchar_t)’ (deleted) 544 | operator<<(basic_ostream<char, _Traits>&, wchar_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:544:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘wchar_t’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:549:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char8_t)’ (deleted) 549 | operator<<(basic_ostream<char, _Traits>&, char8_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:549:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘char8_t’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:554:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char16_t)’ (deleted) 554 | operator<<(basic_ostream<char, _Traits>&, char16_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:554:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘char16_t’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:558:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char32_t)’ (deleted) 558 | operator<<(basic_ostream<char, _Traits>&, char32_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:558:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘char32_t’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:564:5: note: candidate: ‘template<class _Traits> std::basic_ostream<wchar_t, _Traits>& std::operator<<(std::basic_ostream<wchar_t, _Traits>&, char8_t)’ (deleted) 564 | operator<<(basic_ostream<wchar_t, _Traits>&, char8_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:564:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘wchar_t’ and ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:569:5: note: candidate: ‘template<class _Traits> std::basic_ostream<wchar_t, _Traits>& std::operator<<(std::basic_ostream<wchar_t, _Traits>&, char16_t)’ (deleted) 569 | operator<<(basic_ostream<wchar_t, _Traits>&, char16_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:569:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘wchar_t’ and ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:573:5: note: candidate: ‘template<class _Traits> std::basic_ostream<wchar_t, _Traits>& std::operator<<(std::basic_ostream<wchar_t, _Traits>&, char32_t)’ (deleted) 573 | operator<<(basic_ostream<wchar_t, _Traits>&, char32_t) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:573:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘wchar_t’ and ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:594:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const _CharT*)’ 594 | operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s) | ^~~~~~~~ /usr/include/c++/11/ostream:594:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘const _CharT*’ and ‘BigInt’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/ostream:829, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/ostream.tcc:321:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const char*)’ 321 | operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s) | ^~~~~~~~ /usr/include/c++/11/bits/ostream.tcc:321:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const char*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:611:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char*)’ 611 | operator<<(basic_ostream<char, _Traits>& __out, const char* __s) | ^~~~~~~~ /usr/include/c++/11/ostream:611:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const char*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:624:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const signed char*)’ 624 | operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s) | ^~~~~~~~ /usr/include/c++/11/ostream:624:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const signed char*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:629:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const unsigned char*)’ 629 | operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s) | ^~~~~~~~ /usr/include/c++/11/ostream:629:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const unsigned char*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:638:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const wchar_t*)’ (deleted) 638 | operator<<(basic_ostream<char, _Traits>&, const wchar_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:638:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const wchar_t*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:643:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char8_t*)’ (deleted) 643 | operator<<(basic_ostream<char, _Traits>&, const char8_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:643:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const char8_t*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:648:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char16_t*)’ (deleted) 648 | operator<<(basic_ostream<char, _Traits>&, const char16_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:648:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const char16_t*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:652:5: note: candidate: ‘template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char32_t*)’ (deleted) 652 | operator<<(basic_ostream<char, _Traits>&, const char32_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:652:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: cannot convert ‘a’ (type ‘BigInt’) to type ‘const char32_t*’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:658:5: note: candidate: ‘template<class _Traits> std::basic_ostream<wchar_t, _Traits>& std::operator<<(std::basic_ostream<wchar_t, _Traits>&, const char8_t*)’ (deleted) 658 | operator<<(basic_ostream<wchar_t, _Traits>&, const char8_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:658:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘wchar_t’ and ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:663:5: note: candidate: ‘template<class _Traits> std::basic_ostream<wchar_t, _Traits>& std::operator<<(std::basic_ostream<wchar_t, _Traits>&, const char16_t*)’ (deleted) 663 | operator<<(basic_ostream<wchar_t, _Traits>&, const char16_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:663:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘wchar_t’ and ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:667:5: note: candidate: ‘template<class _Traits> std::basic_ostream<wchar_t, _Traits>& std::operator<<(std::basic_ostream<wchar_t, _Traits>&, const char32_t*)’ (deleted) 667 | operator<<(basic_ostream<wchar_t, _Traits>&, const char32_t*) = delete; | ^~~~~~~~ /usr/include/c++/11/ostream:667:5: note: template argument deduction/substitution failed: a.cpp:49:15: note: mismatched types ‘wchar_t’ and ‘char’ 49 | cout<<a<<"+"<<b<<"="<<c<<endl; | ^ In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream:750:5: note: candidate: ‘template<class _Ostream, class _Tp> _Ostream&& std::operator<<(_Ostream&&, const _Tp&)’ 750 | operator<<(_Ostream&& __os, const _Tp& __x) | ^~~~~~~~ /usr/include/c++/11/ostream:750:5: note: template argument deduction/substitution failed: /usr/include/c++/11/ostream: In substitution of ‘template<class _Ostream, class _Tp> _Ostream&& std::operator<<(_Ostream&&, const _Tp&) [with _Ostream = std::basic_ostream<char>&; _Tp = BigInt]’: a.cpp:49:8: required from here /usr/include/c++/11/ostream:750:5: error: template constraint failure for ‘template<class _Os, class _Tp> requires (__derived_from_ios_base<_Os>) && requires(_Os& __os, const _Tp& __t) {__os << __t;} using __rvalue_stream_insertion_t = _Os&&’ /usr/include/c++/11/ostream:750:5: note: constraints not satisfied /usr/include/c++/11/ostream: In substitution of ‘template<class _Os, class _Tp> requires (__derived_from_ios_base<_Os>) && requires(_Os& __os, const _Tp& __t) {__os << __t;} using __rvalue_stream_insertion_t = _Os&& [with _Os = std::basic_ostream<char>&; _Tp = BigInt]’: /usr/include/c++/11/ostream:750:5: required by substitution of ‘template<class _Ostream, class _Tp> _Ostream&& std::operator<<(_Ostream&&, const _Tp&) [with _Ostream = std::basic_ostream<char>&; _Tp = BigInt]’ a.cpp:49:8: required from here /usr/include/c++/11/ostream:717:13: required for the satisfaction of ‘__derived_from_ios_base<_Os>’ [with _Os = std::basic_ostream<char, std::char_traits<char> >&] /usr/include/c++/11/ostream:717:39: note: the expression ‘is_class_v<_Tp> [with _Tp = std::basic_ostream<char, std::char_traits<char> >&]’ evaluated to ‘false’ 717 | concept __derived_from_ios_base = is_class_v<_Tp> | ^~~~~~~~~~~~~~~
11-15
| `cannot convert ‘a’ from type ‘BigInt’ to ‘std::ostream’` | 说明 `operator没正确声明或定义，导致系统找不到匹配的 `函数。✅ 使用 `friend ostream& operator(ostream&, const BigInt&)` 并正确定义 |...
a.cpp: In function ‘int main()’: a.cpp:47:17: error: ‘Swap’ was not declared in this scope 47 | Swap(&a, &b); | ^~~~ a.cpp:53:17: error: ‘Swap’ was not declared in this scope 53 | Swap(&a, &b); | ^~~~ a.cpp:59:17: error: ‘Swap’ was not declared in this scope 59 | Swap(&a, &b); | ^~~~ a.cpp:65:17: error: ‘Swap’ was not declared in this scope 65 | Swap(&a, &b); | ^~~~ a.cpp:71:17: error: ‘Swap’ was not declared in this scope 71 | Swap(&a, &b); | ^~~~ a.cpp:78:21: error: no match for ‘operator>>’ (operand types are ‘std::istream’ {aka ‘std::basic_istream<char>’} and ‘char*’) 78 | cin >> a >> b; | ~~~ ^~ ~ | | | | | char* | std::istream {aka std::basic_istream<char>} In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:168:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 168 | operator>>(bool& __n) | ^~~~~~~~ /usr/include/c++/11/istream:168:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: cannot bind non-const lvalue reference of type ‘bool&’ to a value of type ‘char*’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:172:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]’ (near match) 172 | operator>>(short& __n); | ^~~~~~~~ /usr/include/c++/11/istream:172:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘short int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(short int)a’ to ‘short int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:175:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 175 | operator>>(unsigned short& __n) | ^~~~~~~~ /usr/include/c++/11/istream:175:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘short unsigned int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(short unsigned int)a’ to ‘short unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:179:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]’ (near match) 179 | operator>>(int& __n); | ^~~~~~~~ /usr/include/c++/11/istream:179:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(int)a’ to ‘int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:182:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 182 | operator>>(unsigned int& __n) | ^~~~~~~~ /usr/include/c++/11/istream:182:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘unsigned int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(unsigned int)a’ to ‘unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:186:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 186 | operator>>(long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:186:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘long int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(long int)a’ to ‘long int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:190:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 190 | operator>>(unsigned long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:190:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘long unsigned int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(long unsigned int)a’ to ‘long unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:195:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 195 | operator>>(long long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:195:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘long long int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(long long int)a’ to ‘long long int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:199:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 199 | operator>>(unsigned long long& __n) | ^~~~~~~~ /usr/include/c++/11/istream:199:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: invalid conversion from ‘char*’ to ‘long long unsigned int’ [-fpermissive] 78 | cin >> a >> b; | ^ | | | char* a.cpp:78:24: error: cannot bind rvalue ‘(long long unsigned int)a’ to ‘long long unsigned int&’ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:235:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match) 235 | operator>>(void*& __p) | ^~~~~~~~ /usr/include/c++/11/istream:235:7: note: conversion of argument 1 would be ill-formed: a.cpp:78:24: error: cannot bind non-const lvalue reference of type ‘void*&’ to an rvalue of type ‘void*’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:120:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 120 | operator>>(__istream_type& (*__pf)(__istream_type&)) | ^~~~~~~~ /usr/include/c++/11/istream:120:36: note: no known conversion for argument 1 from ‘char*’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)’ {aka ‘std::basic_istream<char>& (*)(std::basic_istream<char>&)’} 120 | operator>>(__istream_type& (*__pf)(__istream_type&)) | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/istream:124:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]’ 124 | operator>>(__ios_type& (*__pf)(__ios_type&)) | ^~~~~~~~ /usr/include/c++/11/istream:124:32: note: no known conversion for argument 1 from ‘char*’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)’ {aka ‘std::basic_ios<char>& (*)(std::basic_ios<char>&)’} 124 | operator>>(__ios_type& (*__pf)(__ios_type&)) | ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~ /usr/include/c++/11/istream:131:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 131 | operator>>(ios_base& (*__pf)(ios_base&)) | ^~~~~~~~ /usr/include/c++/11/istream:131:30: note: no known conversion for argument 1 from ‘char*’ to ‘std::ios_base& (*)(std::ios_base&)’ 131 | operator>>(ios_base& (*__pf)(ios_base&)) | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~ /usr/include/c++/11/istream:214:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 214 | operator>>(float& __f) | ^~~~~~~~ /usr/include/c++/11/istream:214:25: note: no known conversion for argument 1 from ‘char*’ to ‘float&’ 214 | operator>>(float& __f) | ~~~~~~~^~~ /usr/include/c++/11/istream:218:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 218 | operator>>(double& __f) | ^~~~~~~~ /usr/include/c++/11/istream:218:26: note: no known conversion for argument 1 from ‘char*’ to ‘double&’ 218 | operator>>(double& __f) | ~~~~~~~~^~~ /usr/include/c++/11/istream:222:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ 222 | operator>>(long double& __f) | ^~~~~~~~ /usr/include/c++/11/istream:222:31: note: no known conversion for argument 1 from ‘char*’ to ‘long double&’ 222 | operator>>(long double& __f) | ~~~~~~~~~~~~~^~~ /usr/include/c++/11/istream:259:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]’ 259 | operator>>(__streambuf_type* __sb); | ^~~~~~~~ /usr/include/c++/11/istream:259:36: note: no known conversion for argument 1 from ‘char*’ to ‘std::basic_istream<char>::__streambuf_type*’ {aka ‘std::basic_streambuf<char>*’} 259 | operator>>(__streambuf_type* __sb); | ~~~~~~~~~~~~~~~~~~^~~~ In file included from /usr/include/c++/11/string:56, from /usr/include/c++/11/bits/locale_classes.h:40, from /usr/include/c++/11/bits/ios_base.h:41, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/basic_string.tcc:1485:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)’ 1485 | operator>>(basic_istream<_CharT, _Traits>& __in, | ^~~~~~~~ /usr/include/c++/11/bits/basic_string.tcc:1485:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: mismatched types ‘std::__cxx11::basic_string<_CharT, _Traits, _Allocator>’ and ‘char*’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/istream:1016, from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/bits/istream.tcc:958:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&)’ 958 | operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c) | ^~~~~~~~ /usr/include/c++/11/bits/istream.tcc:958:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: deduced conflicting types for parameter ‘_CharT’ (‘char’ and ‘char*’) 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:756:5: note: candidate: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)’ 756 | operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c) | ^~~~~~~~ /usr/include/c++/11/istream:756:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: cannot convert ‘a’ (type ‘char*’) to type ‘unsigned char&’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:761:5: note: candidate: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)’ 761 | operator>>(basic_istream<char, _Traits>& __in, signed char& __c) | ^~~~~~~~ /usr/include/c++/11/istream:761:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: cannot convert ‘a’ (type ‘char*’) to type ‘signed char&’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:859:5: note: candidate: ‘template<class _CharT, class _Traits, long unsigned int _Num> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT (&)[_Num])’ 859 | operator>>(basic_istream<_CharT, _Traits>& __in, _CharT (&__s)[_Num]) | ^~~~~~~~ /usr/include/c++/11/istream:859:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: mismatched types ‘_CharT [_Num]’ and ‘char*’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:868:5: note: candidate: ‘template<class _Traits, long unsigned int _Num> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char (&)[_Num])’ 868 | operator>>(basic_istream<char, _Traits>& __in, unsigned char (&__s)[_Num]) | ^~~~~~~~ /usr/include/c++/11/istream:868:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: mismatched types ‘unsigned char [_Num]’ and ‘char*’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:873:5: note: candidate: ‘template<class _Traits, long unsigned int _Num> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char (&)[_Num])’ 873 | operator>>(basic_istream<char, _Traits>& __in, signed char (&__s)[_Num]) | ^~~~~~~~ /usr/include/c++/11/istream:873:5: note: template argument deduction/substitution failed: a.cpp:78:24: note: mismatched types ‘signed char [_Num]’ and ‘char*’ 78 | cin >> a >> b; | ^ In file included from /usr/include/c++/11/iostream:40, from a.cpp:1: /usr/include/c++/11/istream:1006:5: note: candidate: ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&)’ 1006 | operator>>(_Istream&& __is, _Tp&& __x) | ^~~~~~~~ /usr/include/c++/11/istream:1006:5: note: template argument deduction/substitution failed: /usr/include/c++/11/istream: In substitution of ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&) [with _Istream = std::basic_istream<char>&; _Tp = char*&]’: a.cpp:78:10: required from here /usr/include/c++/11/istream:1006:5: error: template constraint failure for ‘template<class _Is, class _Tp> requires (__derived_from_ios_base<_Is>) && requires(_Is& __is, _Tp&& __t) {__is >> (forward<_Tp>)(__t);} using __rvalue_stream_extraction_t = _Is&&’ /usr/include/c++/11/istream:1006:5: note: constraints not satisfied In file included from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/ostream: In substitution of ‘template<class _Is, class _Tp> requires (__derived_from_ios_base<_Is>) && requires(_Is& __is, _Tp&& __t) {__is >> (forward<_Tp>)(__t);} using __rvalue_stream_extraction_t = _Is&& [with _Is = std::basic_istream<char>&; _Tp = char*&]’: /usr/include/c++/11/istream:1006:5: required by substitution of ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&) [with _Istream = std::basic_istream<char>&; _Tp = char*&]’ a.cpp:78:10: required from here /usr/include/c++/11/ostream:717:13: required for the satisfaction of ‘__derived_from_ios_base<_Is>’ [with _Is = std::basic_istream<char, std::char_traits<char> >&] /usr/include/c++/11/ostream:717:39: note: the expression ‘is_class_v<_Tp> [with _Tp = std::basic_istream<char, std::char_traits<char> >&]’ evaluated to ‘false’ 717 | concept __derived_from_ios_base = is_class_v<_Tp> | ^~~~~~~~~~~~~~~ a.cpp:79:17: error: ‘Swap’ was not declared in this scope 79 | Swap(a, b); | ^~~~ a.cpp:42:19: warning: unused variable ‘n’ [-Wunused-variable] 42 | int type, n, i; | ^ a.cpp:42:22: warning: unused variable ‘i’ [-Wunused-variable] 42 | int type, n, i; | ^ 上一个问题的代码出现了上述报错，请修改
05-29
通常，处理C风格字符串的输入应该使用字符数组或者std::string，但根据问题描述，用户可能需要处理char*类型，所以这里可能需要特别的处理方式，比如先分配内存，或者使用临时缓冲区。 另外，还有警告指出变量n和i...
error C2664: 'CreateWindowExW' : cannot convert parameter 2 from 'const char [16]' to 'LPCWSTR'
tmy257的专栏
12-01 1713
在VC6++的代码运行没问题，在VS2012下运行出现了这个问题。这应该与字符集和字符串转换有关，使用强制类型转换效果不理想。 解决方法：项目(PROJECT)-->属性(properties)-->配置属性(Configuration properties)-->常规(general)-->字符集(Character set)-->使用多字节字符集(Use Multi-Byte Chara
关于VS2005的error C2664: cannot convert parameter 2 from 'const char [2]' to 'LPCWSTR
tansitongba
02-15 336
一、VS2005设置UNICODE或ASCII字符集问题 VS2005开发程序时，默认的字符集是Unicode。所以如果程序中使用字符常量一定要显示转换为Unicode型，否则编译时报错。 如果你不希望程序支持Unicode字符集，更改项目设置就可以了。 project-&gt;properties-&gt;configurations Properties -&gt; General -&...
error C2664: 'cvSetMouseCallback' : cannot convert parameter 2 from 'void (__cdecl *)(int,int,int,int)' to 'CvMouseCallback' 的解决
斯凡的专栏
03-14 6429
<br />    正如上文中提到的，在mfc中，cvSetMouseCallback（）函数总是会提示如标题的错误提示，在查阅了网页和参考书，解决方法，如下：<br />    在头文件中，将要调用的函数：on_mouse声明为静态成员函数<br /> <br />    static void on_mouse(int event, int x, int y, int flags, void *param);<br /> <br />   在on_mouse（）函数中添加如下代码：<br />   如果
error C2664: 'cvSetMouseCallback' : cannot convert parameter 2 from ....to'CvMouseback'
成长之路
05-08 861
error C2664: 'cvSetMouseCallback' : cannot convert parameter 2 from 'void (__cdecl *)(int,int,int,int)' to 'CvMouseCallback' 的解决方法    正如上文中提到的，在mfc中，cvSetMouseCallback（）函数总是会提示如标题的错误提示，在查阅了网页和参
对有关数据类型转换的整理
特权份子的专栏
09-30 1094
[Z]对有关数据类型转换的整理     int i = 100; long l = 2001; float f=300.2; double d=12345.119; char username[]="fsdfaffasf"; char temp[200]; cha
error C2664: “MessageBoxA”: 不能将参数 2 从“std::string”转换为“LPCSTR”
dianfeng0344的专栏
07-16 3949
错误 1 error C2664: “MessageBoxA”: 不能将参数 2 从“std::string”转换为“LPCSTR” E:\Work\Example_Project\JWSoftRegDlg\JWSoftRegDlg\JWSoftRegDlgDlg.cpp 141 1 JWSoftRegDlg 处理方法:将string加.c_str().
error C2664: 'printFreq' : cannot convert parameter 1 from 'unsigned char [256]' to 'char []
05-11
你调用了一个函数printFreq，它需要一个char类型的数组作为参数，但是你传递的是一个unsigned char类型的数组。 你可以将函数的参数类型改为unsigned char类型，或者将传递给函数的数组转换为char类型的数组。 ...
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