g++ warn_unused_result

最新推荐文章于 2024-08-29 13:33:31 发布
最新推荐文章于 2024-08-29 13:33:31 发布
阅读量5.1k 收藏 8
点赞数
CC 4.0 BY-SA版权
分类专栏： c++ tips 文章标签： g++ warn_unused_result
版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。
本文链接：https://blog.youkuaiyun.com/carbon06/article/details/82017545

介绍

在编程过程中，有的函数我们需要确保函数的返回值必须被使用。但是如果函数使用者直接调用函数且不使用函数的返回值的话，g++ 不会给出warning。这样可能会导致很难寻觅的bug。如调用realloc函数，函数调用者必须使用函数的返回值获得重新分配内存的指针。
利用g++ common function attributes 中提供的warn_unused_result 可以保证函数的返回值在没有被使用的时候提示warning，如果在编译选项添加-Werror, 则在编译时就会提示编译错误。关于更多 g++ common function attributes 参见https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html

示例

测试代码如下

/****************************************
最低0.47元/天 解锁文章

200万优质内容无限畅学
g++ warning option
静思阁
03-14 2380
g++ warning可以分成三类: 1. -Wall  定义所有构造相关的警告, 用户觉得可疑的, 易规避的, 甚至宏联合的警告. -Wall 包含以下warning flags: -Waddress -Warray-bounds (须与-O2联用) -Wc++0x-compat -Wchar-subscripts -Wimplicit-int -Wimplicit-function-d
c语言中的warn函数用法,关于c ++：MSVC等同于__attribute__((warn_unused_result))？
weixin_35390150的博客
05-23 1201
我发现__attribute__ ((warn_unused_result))作为鼓励开发人员不要忽略函数返回的错误代码的一种非常有用的方法，但是我需要将它与MSVC以及gcc和gcc兼容的编译器(例如ICC)一起使用。 Microsoft Visual Studio C / C ++编译器是否具有等效的机制？ (到目前为止，我已经尝试通过MSDN进行尝试，但是没有任何运气。)当然，这叫做例外。@...
编译出现 warn_unused_result -Wunused-result 如何解决
summer的博客
12-02 6862
ignoring return value of ‘int RUN_ALL_TESTS()’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 根据这个提示可以猜测编译的传递-Wno-unused-result可以解决，确实解决了
Linux内核warn_unused_result [-Werror=unused-result]报错问题
程序改变生活
04-16 1万+
一、修改顶层Makefile 1.declared with attribute warn_unused_result [-Werror=unused-result] KBUILD_CFLAGS += -Wno-error=unused-result \ -Werror=return-type 表示忽略unused-result警告；但是return-type警告
【关于PTA平台中出现的问题】warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result
sinat_40936062的博客
11-22 10万+
这段英文警告：意思是，scanf的返回值正在被忽略，在warn_unused_result中有说明。 直接定位问题：你的程序忽略了`scanf`的值，这可能会产生一些问题，所以GCC编译器给了你一个警告。 解决办法：(1)用条件判断语句对`scanf`的内容进行判断保护，避免输入非法字符，导致返回值为0或者出错。(2)`warning`不会对程序本身逻辑造成影响，忽略即可。程序未通过测试，要检查代码本身的错误。
a.cpp: In function ‘int main()’: a.cpp:11:10: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 11 | scanf("%d",&n); | ~~~~~^~~~~~~~~ a.cpp:13:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 13 | scanf("%d ",&c); | ~~~~~^~~~~~~~~~ a.cpp:16:18: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 16 | scanf("%c",&r); | ~~~~~^~~~~~~~~
04-03
g++ -Wno-unused-result your_code.cpp ``` **缺点**：全局生效，可能掩盖其他重要警告。 --- ### 最佳实践 1. **优先使用方法1**，确保程序健壮性。 2. 若确定无需处理返回值（如调试代码），临时使用方法2。 3. ...
在WSL中编译C程序出现编译警告 root@DESKTOP-2QBDJV0:/mnt/d/work/openeuler_env/code/testUsbDongleRFID_pro# ./script/build.sh -- The C compiler identification is GNU 10.3.1 -- The CXX compiler identification is GNU 10.3.1 -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working C compiler: /mnt/d/work/openeuler_env/oecore-x86_64/sysroots/x86_64-peesdk-linux/usr/bin/aarch64-powereuler-linux-gcc - skipped -- Detecting C compile features -- Detecting C compile features - done -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /mnt/d/work/openeuler_env/oecore-x86_64/sysroots/x86_64-peesdk-linux/usr/bin/aarch64-powereuler-linux-g++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done -- Generating done -- Build files have been written to: /mnt/d/work/openeuler_env/code/testUsbDongleRFID_pro/build make: Warning: File 'Makefile' has modification time 0.31 s in the future make[1]: Warning: File 'CMakeFiles/Makefile2' has modification time 0.28 s in the future make[2]: Warning: File 'CMakeFiles/run_testUsbDongleRFID.dir/flags.make' has modification time 0.21 s in the future make[2]: warning: Clock skew detected. Your build may be incomplete. make[2]: Warning: File 'CMakeFiles/run_testUsbDongleRFID.dir/flags.make' has modification time 0.17 s in the future [ 50%] Building C object CMakeFiles/run_testUsbDongleRFID.dir/main.c.o /mnt/d/work/openeuler_env/code/testUsbDongleRFID_pro/main.c: In function 'main': /mnt/d/work/openeuler_env/code/testUsbDongleRFID_pro/main.c:121:5: warning: ignoring return value of 'write' declared with attribute 'warn_unused_result' [-Wunused-result] 121 | write(fd, command, strlen(command)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [100%] Linking C executable run_testUsbDongleRFID make[2]: warning: Clock skew detected. Your build may be incomplete. [100%] Built target run_testUsbDongleRFID make[1]: warning: Clock skew detected. Your build may be incomplete. make: warning: Clock skew detected. Your build may be incomplete.
06-12
编译器（尤其是开启了 `-Wall` 或 `-Wunused-result` 选项时）发出警告，是因为你调用了 `write` 但没有检查这个返回值是否表示成功、部分成功或失败。 * **后果：** 如果不检查返回值： * 你可能无法得知写入操作...
[proc] 执行命令: D:\CMake\bin\cmake.EXE --version [proc] 执行命令: D:\CMake\bin\cmake.EXE -E capabilities [kit] 已成功从 C:\Users\暴雨\AppData\Local\CMakeTools\cmake-tools-kits.json 加载 11 工具包 [variant] 已加载一组新变量 [proc] 执行命令: D:\mingw64\bin\gcc.exe -v [main] 正在配置项目: lv_port_pc_eclipse-release-v8.3 [proc] 执行命令: D:\CMake\bin\cmake.EXE -DCMAKE_BUILD_TYPE:STRING=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_C_COMPILER:FILEPATH=D:\mingw64\bin\gcc.exe -DCMAKE_CXX_COMPILER:FILEPATH=D:\mingw64\bin\g++.exe --no-warn-unused-cli -SF:/Project_do/lv_port_pc_eclipse-release-v8.3 -Bf:/Project_do/lv_port_pc_eclipse-release-v8.3/build -G "MinGW Makefiles" [cmake] Not searching for unused variables given on the command line. [cmake] CMake Error: The current CMakeCache.txt directory F:/Project_do/lv_port_pc_eclipse-release-v8.3/build/CMakeCache.txt is different than the directory d:/下载文件/lv_port_pc_eclipse-release-v8.3/build where CMakeCache.txt was created. This may result in binaries being created in the wrong place. If you are not sure, reedit the CMakeCache.txt [cmake] CMake Error: The source "F:/Project_do/lv_port_pc_eclipse-release-v8.3/CMakeLists.txt" does not match the source "D:/下载文件/lv_port_pc_eclipse-release-v8.3/CMakeLists.txt" used to generate cache. Re-run cmake with a different source directory. [proc] 命令“D:\CMake\bin\cmake.EXE -DCMAKE_BUILD_TYPE:STRING=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_C_COMPILER:FILEPATH=D:\mingw64\bin\gcc.exe -DCMAKE_CXX_COMPILER:FILEPATH=D:\mingw64\bin\g++.exe --no-warn-unused-cli -SF:/Project_do/lv_port_pc_eclipse-release-v8.3 -Bf:/Project_do/lv_port_pc_eclipse-release-v8.3/build -G "MinGW Makefiles"”已退出，代码为 1
03-24
好的，用户遇到了CMake构建时的路径不匹配问题，具体错误是生成二进制文件的位置错误以及源码目录与缓存不符。我需要先理解问题的原因，然后找出解决方案。 首先，CMake在构建项目时会生成缓存文件，记录配置信息，...
安装 报错npm WARN deprecated npmlog@4.1.2: This package is no longer supported. npm WARN deprecated are-we-there-yet@1.1.7: This package is no longer supported. npm WARN deprecated gauge@2.7.4: This package is no longer supported. npm ERR! code 1 npm ERR! path /Users/yangjia/workspace/company/dkYun/SDK2.0/node_modules/microtime npm ERR! command failed npm ERR! command sh -c prebuild-install || node-gyp rebuild npm ERR! CXX(target) Release/obj.target/microtime/src/microtime.o npm ERR! gyp info it worked if it ends with ok npm ERR! gyp info using node-gyp@8.4.1 npm ERR! gyp info using node@16.14.0 | darwin | arm64 npm ERR! gyp info find Python using Python version 3.12.1 found at "/Library/Frameworks/Python.framework/Versions/3.12/bin/python3" npm ERR! gyp info spawn /Library/Frameworks/Python.framework/Versions/3.12/bin/python3 npm ERR! gyp info spawn args [ npm ERR! gyp info spawn args '/usr/local/lib/node_modules/npm/node_modules/node-gyp/gyp/gyp_main.py', npm ERR! gyp info spawn args 'binding.gyp', npm ERR! gyp info spawn args '-f', npm ERR! gyp info spawn args 'make', npm ERR! gyp info spawn args '-I', npm ERR! gyp info spawn args '/Users/yangjia/workspace/company/dkYun/SDK2.0/node_modules/microtime/build/config.gypi', npm ERR! gyp info spawn args '-I', npm ERR! gyp info spawn args '/usr/local/lib/node_modules/npm/node_modules/node-gyp/addon.gypi', npm ERR! gyp info spawn args '-I', npm ERR! gyp info spawn args '/Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/common.gypi', npm ERR! gyp info spawn args '-Dlibrary=shared_library', npm ERR! gyp info spawn args '-Dvisibility=default', npm ERR! gyp info spawn args '-Dnode_root_dir=/Users/yangjia/Library/Caches/node-gyp/16.14.0', npm ERR! gyp info spawn args '-Dnode_gyp_dir=/usr/local/lib/node_modules/npm/node_modules/node-gyp', npm ERR! gyp info spawn args '-Dnode_lib_file=/Users/yangjia/Library/Caches/node-gyp/16.14.0/<(target_arch)/node.lib', npm ERR! gyp info spawn args '-Dmodule_root_dir=/Users/yangjia/workspace/company/dkYun/SDK2.0/node_modules/microtime', npm ERR! gyp info spawn args '-Dnode_engine=v8', npm ERR! gyp info spawn args '--depth=.', npm ERR! gyp info spawn args '--no-parallel', npm ERR! gyp info spawn args '--generator-output', npm ERR! gyp info spawn args 'build', npm ERR! gyp info spawn args '-Goutput_dir=.' npm ERR! gyp info spawn args ] npm ERR! gyp info spawn make npm ERR! gyp info spawn args [ 'BUILDTYPE=Release', '-C', 'build' ] npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:222: npm ERR! In file included from ../../nan/nan_converters.h:67: npm ERR! ../../nan/nan_converters_43_inl.h:22:1: error: no viable conversion from 'Local<v8::Context>' to 'v8::Isolate *' npm ERR! X(Boolean) npm ERR! ^~~~~~~~~~ npm ERR! ../../nan/nan_converters_43_inl.h:18:23: note: expanded from macro 'X' npm ERR! val->To ## TYPE(isolate->GetCurrentContext()) \ npm ERR! ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:3086:37: note: passing argument to parameter 'isolate' here npm ERR! Local<Boolean> ToBoolean(Isolate* isolate) const; npm ERR! ^ npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:222: npm ERR! In file included from ../../nan/nan_converters.h:67: npm ERR! ../../nan/nan_converters_43_inl.h:22:1: error: no member named 'FromMaybe' in 'v8::Local<v8::Boolean>' npm ERR! X(Boolean) npm ERR! ^~~~~~~~~~ npm ERR! ../../nan/nan_converters_43_inl.h:19:12: note: expanded from macro 'X' npm ERR! .FromMaybe(v8::Local<v8::TYPE>())); \ npm ERR! ^ npm ERR! ../../nan/nan_converters_43_inl.h:40:1: error: no viable conversion from 'Local<v8::Context>' to 'v8::Isolate *' npm ERR! X(bool, Boolean) npm ERR! ^~~~~~~~~~~~~~~~ npm ERR! ../../nan/nan_converters_43_inl.h:37:29: note: expanded from macro 'X' npm ERR! return val->NAME ## Value(isolate->GetCurrentContext()); \ npm ERR! ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:3096:30: note: passing argument to parameter 'isolate' here npm ERR! bool BooleanValue(Isolate* isolate) const; npm ERR! ^ npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:222: npm ERR! In file included from ../../nan/nan_converters.h:67: npm ERR! ../../nan/nan_converters_43_inl.h:40:1: error: no viable conversion from returned value of type 'bool' to function return type 'imp::ToFactory<bool>::return_t' (aka 'Maybe<bool>') npm ERR! X(bool, Boolean) npm ERR! ^~~~~~~~~~~~~~~~ npm ERR! ../../nan/nan_converters_43_inl.h:37:10: note: expanded from macro 'X' npm ERR! return val->NAME ## Value(isolate->GetCurrentContext()); \ npm ERR! ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:10437:7: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'bool' to 'const v8::Maybe<bool> &' for 1st argument npm ERR! class Maybe { npm ERR! ^ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:10437:7: note: candidate constructor (the implicit move constructor) not viable: no known conversion from 'bool' to 'v8::Maybe<bool> &&' for 1st argument npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:10492:12: note: explicit constructor is not a candidate npm ERR! explicit Maybe(const T& t) : has_value_(true), value_(t) {} npm ERR! ^ npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:223: npm ERR! In file included from ../../nan/nan_new.h:189: npm ERR! ../../nan/nan_implementation_12_inl.h:356:37: error: too few arguments to function call, expected 2, have 1 npm ERR! return v8::StringObject::New(value).As<v8::StringObject>(); npm ERR! ~~~~~~~~~~~~~~~~~~~~~ ^ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:6196:23: note: 'New' declared here npm ERR! static Local<Value> New(Isolate* isolate, Local<String> value); npm ERR! ^ npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:2722: npm ERR! ../../nan/nan_object_wrap.h:24:25: error: no member named 'IsNearDeath' in 'Nan::Persistent<v8::Object>' npm ERR! assert(persistent().IsNearDeath()); npm ERR! ~~~~~~~~~~~~ ^ npm ERR! /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/assert.h:99:25: note: expanded from macro 'assert' npm ERR! (__builtin_expect(!(e), 0) ? __assert_rtn(__func__, __ASSERT_FILE_NAME, __LINE__, #e) : (void)0) npm ERR! ^ npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:2722: npm ERR! ../../nan/nan_object_wrap.h:127:26: error: no member named 'IsNearDeath' in 'Nan::Persistent<v8::Object>' npm ERR! assert(wrap->handle_.IsNearDeath()); npm ERR! ~~~~~~~~~~~~~ ^ npm ERR! /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/assert.h:99:25: note: expanded from macro 'assert' npm ERR! (__builtin_expect(!(e), 0) ? __assert_rtn(__func__, __ASSERT_FILE_NAME, __LINE__, #e) : (void)0) npm ERR! ^ npm ERR! In file included from ../src/microtime.cc:9: npm ERR! In file included from ../../nan/nan.h:2818: npm ERR! ../../nan/nan_typedarray_contents.h:34:43: warning: 'GetContents' is deprecated: Use GetBackingStore. See http://crbug.com/v8/9908. [-Wdeprecated-declarations] npm ERR! data = static_cast<char*>(buffer->GetContents().Data()) + byte_offset; npm ERR! ^ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:5614:3: note: 'GetContents' has been explicitly marked deprecated here npm ERR! V8_DEPRECATED("Use GetBackingStore. See http://crbug.com/v8/9908.") npm ERR! ^ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8config.h:454:35: note: expanded from macro 'V8_DEPRECATED' npm ERR! # define V8_DEPRECATED(message) [[deprecated(message)]] npm ERR! ^ npm ERR! ../src/microtime.cc:75:10: error: no matching member function for call to 'Set' npm ERR! array->Set(Nan::New<v8::Integer>(0), Nan::New<v8::Number>((double)t.tv_sec)); npm ERR! ~~~~~~~^~~ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:3961:37: note: candidate function not viable: requires 3 arguments, but 2 were provided npm ERR! V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, npm ERR! ^ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:3964:37: note: candidate function not viable: requires 3 arguments, but 2 were provided npm ERR! V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index, npm ERR! ^ npm ERR! ../src/microtime.cc:76:10: error: no matching member function for call to 'Set' npm ERR! array->Set(Nan::New<v8::Integer>(1), Nan::New<v8::Number>((double)t.tv_usec)); npm ERR! ~~~~~~~^~~ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:3961:37: note: candidate function not viable: requires 3 arguments, but 2 were provided npm ERR! V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, npm ERR! ^ npm ERR! /Users/yangjia/Library/Caches/node-gyp/16.14.0/include/node/v8.h:3964:37: note: candidate function not viable: requires 3 arguments, but 2 were provided npm ERR! V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index, npm ERR! ^ npm ERR! 1 warning and 9 errors generated. npm ERR! make: *** [Release/obj.target/microtime/src/microtime.o] Error 1 npm ERR! gyp ERR! build error npm ERR! gyp ERR! stack Error: `make` failed with exit code: 2 npm ERR! gyp ERR! stack at ChildProcess.onExit (/usr/local/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:194:23) npm ERR! gyp ERR! stack at ChildProcess.emit (node:events:520:28) npm ERR! gyp ERR! stack at Process.ChildProcess._handle.onexit (node:internal/child_process:291:12) npm ERR! gyp ERR! System Darwin 22.6.0 npm ERR! gyp ERR! command "/usr/local/bin/node" "/usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild" npm ERR! gyp ERR! cwd /Users/yangjia/workspace/company/dkYun/SDK2.0/node_modules/microtime npm ERR! gyp ERR! node -v v16.14.0 npm ERR! gyp ERR! node-gyp -v v8.4.1 npm ERR! gyp ERR! not ok npm ERR! A complete log of this run can be found in: npm ERR! /Users/yangjia/.npm/_logs/2025-06-30T06_40_09_765Z-debug-0.log
最新发布
07-01
注意：非Windows系统（如macOS、Linux）的解决方案略有不同，主要需要安装gcc/g++和make等基础编译工具。例如在Ubuntu上：```bashsudo apt-get installbuild-essential```引用说明： [^1]:引用自清除node-gyp缓存和...
"忽略' scanf '的返回值，用属性warn_unused_result声明"的疑问
Lumos_123的博客
02-24 1万+
刚开始C程序设计基础这门课，目前停留在简单的“hello　world”阶段。 遇到稍复杂的题目，比如温度的转换，几乎每次都会出现“ warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]    scanf("%lf %lf",&amp;lower...
[PTA报错]warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result
热门推荐
weixin_44164333的博客
02-24 10万+
PTA刷题时总是出现如标题所示的报错——警告: 忽略‘ scanf’的返回值，用属性 warn_unused_result 声明之类的，于是对出现报错的原因和解决方法做了查阅。 原因 我们经常也能在编译器中看到到未处理scanf返回值的警告，但我们往往选择忽略，PTA太严格了！只有解决这个警告，无奈~ 首先scanf 函数的返回值反映了按照指定的格式符正确读入的数据的个数。不一定等于得到输入值的输...
warning: expression result unuesd 可能原因是函数忘了加括号,
weixin_30794499的博客
05-24 1万+
转载于:https://www.cnblogs.com/chulin/p/9082833.html
Ansible 中的错误处理
wushengT的博客
08-29 698
良好的错误处理可以帮助你在任务失败时采取适当的措施，确保系统的稳定性和一致性。允许你在任务组（block）中处理错误，并在遇到错误时执行备用任务。可以在任务完成后，无论成功还是失败，执行某些任务。你可以在任务中设置条件来判断任务是否真正失败。使用 Ansible 的日志功能和调试模块来记录任务执行情况和错误信息，有助于问题排查和报告。通过以上方法，你可以在 Ansible 中有效地处理错误，提高任务的鲁棒性和系统的稳定性。用于重试机制，在任务失败时重试任务直到成功或达到最大重试次数。
关于C语言一些不起眼的小错误
zhaoen95的博客
04-18 1万+
关于C语言一些不起眼的小错误,这是一些入门时候容易遇到的小错误,但他也许会伴随你很久~
Swift的高阶函数
kyl282889543的博客
07-24 3243
Swift的高阶函数swift常用高阶函数1. map2. flatMap3. filter4. reduce swift常用高阶函数 swift中比较常用的高阶函数有：map、flatMap、filter、reduce 1. map map可以对数组中的每一个元素做一次处理 // 计算字符串的长度 let stringArray = ["Objective-C", "Swift", "HTML"...
Warning: ignoring return value of 'scanf', declared with attribute warn_unused_result
K8sCat
03-01 6万+
#include &lt;stdio.h&gt; int main() { int t; scanf("%d", &amp;t); printf("%d", t); return 0; } 提示： prog.c: In function ‘main’: prog.c:5: warning: ignoring return value of ‘scanf’, de...
warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-res
qiu_huohuo
03-04 2万+
在PAT上写C代码的时候出现warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] 原因：使用scanf的时候有一个返回值 #include <stdio.h> int main() { int a; s...
08.如何处理编译器的警告
qq_38307618的博客
12-16 2181
在编写代码时，我们常常为了方便去忽略编译器告诉我们的代码存在的警告。但其实编译器是非常有用的，如果我们使用得当，将会省去大量的debug时间。 在gcc编译时，加上后缀 -Werror 把所有的警告都视作为错误。 当我们遇到一些我们真的需要忽略编译器告警时，将这种忽略维持在局部。 我们来看一个例子： -Werror=unused-result gcc -O2 -Wall -Werror -o gen-expr gen-expr.c gen-expr.c: In function ‘m.
mpi程序运行报错
weixin_34220623的博客
06-11 1131
通过yum直接安装mpi环境之后，发现会报错。具体报错内容如下，始终解决不了。 [root@local ~]# mpicc -o test ./test.c ./test.c: 在函数‘random_A_B’中: 第一个报错，主要是通过源码编译安装了一遍MPI解决问题，源码安装可以参考我的博客的mpi环境安装 ./test.c:24:11: 警告：忽略声明有 warn_unused_resul...
评论 1
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付：10.00元
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
实付元
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