C++编译错误cannot have cv-qualifier

本文详细解释了C++中const关键字用于非静态成员函数声明的意义,以及volatile关键字用于确保非静态成员函数线程安全的方法。通过实例演示了正确使用这两个关键字的重要性,并指出了不当使用的错误提示。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

const关键字放在非静态成员函数声明的尾部,表示该非静态成员函数不修改对象内容。volatile关键字放到非静态函数声明的尾部,表示该非静态成员函数是线程安全的。注意他们都只能放到非静态成员函数声明的尾部,否则会产生如下报错:
error: non-member function 'xxx' cannot have cv-qualifier

放到非成员函数声明的尾部

#include <iostream>

using namespace std;

double getSqureArea(int a) const
{
    return a * a;
}


int main(int arg, char *argv[])
{
    cout << getSqureArea(2) << endl;
    return 0;
}
编译上面的C++程序,报错如下:
g++ -c const_volatile_test.cpp -o const_volatile_test.o
const_volatile_test.cpp:12:28: error: non-member function 'double getSqureArea(int)' cannot have cv-qualifier

放到静态成员函数声明的尾部

#include <iostream>

using namespace std;

class CStatic
{
    private:
    static int static_value;
    public:
    static int get_static_value() const
    {
        return static_value;
    }
};

int CStatic::static_value = 1;
int main(int argc,char *argv[])
{
    cout << CStatic::get_static_value()<<endl;
    return 0;
}
编译上面的C++程序,报错如下:
g++ -c const_volatile_test.cpp -o const_volatile_test.o
const_volatile_test.cpp:17:39: error: static member function 'static int CStatic::get_static_value()' cannot have cv-qualifier

 

转载于:https://www.cnblogs.com/jiangxinnju/p/5516904.html

a.cpp:9:49: error: non-member function ‘Complex operator-(Complex&)’ cannot have cv-qualifier 9 | friend Complex operator-( Complex &c3 ) const;//重载双目运算符'-' | ^~~~~ a.cpp:25:9: error: no declaration matches ‘Complex Complex::operator-=(Complex&) const’ 25 | Complex Complex::operator-=(Complex &c2)const | ^~~~~~~ a.cpp:8:17: note: candidate is: ‘Complex Complex::operator-=(Complex&)’ 8 | Complex operator-=( Complex &c2 ); //重载双目运算符'-=' | ^~~~~~~~ a.cpp:3:7: note: ‘class Complex’ defined here 3 | class Complex | ^~~~~~~ a.cpp:31:9: error: no declaration matches ‘Complex Complex::operator-(Complex&) const’ 31 | Complex Complex::operator-(Complex &c3)const | ^~~~~~~ a.cpp:31:9: note: no functions named ‘Complex Complex::operator-(Complex&) const’ a.cpp:3:7: note: ‘class Complex’ defined here 3 | class Complex | ^~~~~~~ a.cpp: In function ‘int main()’: a.cpp:44:12: error: no match for ‘operator-’ (operand types are ‘Complex’ and ‘Complex’) 44 | c3 = c1-c2; | ~~^~~ | | | | | Complex | Complex In file included from /usr/include/c++/11/bits/stl_algobase.h:67, from /usr/include/c++/11/bits/char_traits.h:39, from /usr/include/c++/11/ios:40, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/stl_iterator.h:577:5: note: candidate: ‘template<class _IteratorL, class _IteratorR> constexpr decltype ((__y.base() - __x.base())) std::operator-(const std::reverse_iterator<_IteratorL>&, const std::reverse_iterator<_IteratorR>&)’ 577 | operator-(const reverse_iterator<_IteratorL>& __x, | ^~~~~~~~ /usr/include/c++/11/bits/stl_iterator.h:577:5: note: template argument deduction/substitution failed: a.cpp:44:13: note: ‘Complex’ is not derived from ‘const std::reverse_iterator<_IteratorL>’ 44 | c3 = c1-c2; | ^~ In file included from /usr/include/c++/11/bits/stl_algobase.h:67, from /usr/include/c++/11/bits/char_traits.h:39, from /usr/include/c++/11/ios:40, from /usr/include/c++/11/ostream:38, from /usr/include/c++/11/iostream:39, from a.cpp:1: /usr/include/c++/11/bits/stl_iterator.h:1693:5: note: candidate: ‘template<class _IteratorL, class _IteratorR> constexpr decltype ((__x.base() - __y.base())) std::operator-(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)’ 1693 | operator-(const move_iterator<_IteratorL>& __x, | ^~~~~~~~ /usr/include/c++/11/bits/stl_iterator.h:1693:5: note: template argument deduction/substitution failed: a.cpp:44:13: note: ‘Complex’ is not derived from ‘const std::move_iterator<_IteratorL>’ 44 | c3 = c1-c2; | ^~ a.cpp:9:24: note: candidate: ‘Complex operator-(Complex&)’ 9 | friend Complex operator-( Complex &c3 ) const;//重载双目运算符'-' | ^~~~~~~~ a.cpp:9:24: note: candidate expects 1 argument, 2 provided 确
05-07
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值