c – 断言(true)警告有符号/无符号不匹配

Visual Studio 2008,调试版本.这行C

assert(true);

导致投诉

warning C4365: 'argument' : conversion from 'long' to 'unsigned int', signed/unsigned mismatch

使用任何(有用的)布尔表达式替换true时,警告仍然存在,即使使用1ul也是如此.

仅供参考,编译器的文件assert.h是：

#define assert(_Expression) (void)( (!!(_Expression)) || (_wassert(_CRT_WIDE(#_Expression), _CRT_WIDE(__FILE__), __LINE__), 0) )
extern "C" _CRTIMP void __cdecl _wassert(_In_z_ const wchar_t * _Message, _In_z_ const wchar_t *_File, _In_ unsigned _Line);

如何在不压制所有C4365的情况下彻底抑制这个警告？这是__LINE__的错吗？

解决方法:

The bug report explains it very well：

This issue occurs because __LINE__ is of type long, and the assert
macro passes __LINE__ as an argument to the _wassert function, which
expects an unsigned int. When not compiling with /ZI, __LINE__ is a
constant expression, so the compiler can statically determine that the
conversion to unsigned int will result in the same value. When
compiling with /ZI, __LINE__ is not a constant expression, so the
compiler cannot statically determine that the conversion will result
in the same value and it issues warning C4365.

它还提供了一个解决方法：

As a workaround for this issue, I would recommend #undefing assert in
your source code, and re-#define-ing it, using the same definition as
in <assert.h>, but with a cast to suppress the warning.

请注意,此错误似乎已从MSVC2015开始修复.

标签：c,assert,suppress-warnings,visual-studio-2008
来源： https://codeday.me/bug/20190829/1760316.html