warning C28251: Inconsistent annotation for function

[Riadela]

When I'm building my solution in release mode I keep getting this warning which is treated as an error. Specifically it happens in some files in the winapi folder, such as get_last_error.hpp, on the GetLastError function

I dont want to use pragma disable warning on my projects, does anyone have any idea of why this happens..?

[Lastique]

1. What Windows SDK and compiler are you using?
2. Can you identify the difference between Boost.WinAPI and Windows SDK declarations?

As a workaround you can define BOOST_USE_WINDOWS_H when building your code to force Boost.WinAPI use windows.h instead of declaring functions and types on its own.

[Riadela]

I'm on SDK 10.0.17134 and using VS17 (msvc 141) Yeah I can list a couple of them that I get as an error get_last_error.hpp BOOST_SYMBOL_IMPORT boost::winapi::DWORD_ BOOST_WINAPI_WINAPI_CC GetLastError(BOOST_WINAPI_DETAIL_VOID);

errhandling.h (from my windows kits)

#ifndef _M_CEE_PURE

WINBASEAPI _Check_return_ 
_Post_equals_last_error_
DWORD
WINAPI
GetLastError(
    VOID
    );
#endif

Or in boost again in error_handling.hpp

BOOST_SYMBOL_IMPORT boost::winapi::DWORD_ BOOST_WINAPI_WINAPI_CC
FormatMessageA(
    boost::winapi::DWORD_ dwFlags,
    boost::winapi::LPCVOID_ lpSource,
    boost::winapi::DWORD_ dwMessageId,
    boost::winapi::DWORD_ dwLanguageId,
    boost::winapi::LPSTR_ lpBuffer,
    boost::winapi::DWORD_ nSize,
    va_list *Arguments);

And in my sdk in WinBase.h

#if !defined(MIDL_PASS)
WINBASEAPI
_Success_(return != 0)
DWORD
WINAPI
FormatMessageA(
    _In_     DWORD dwFlags,
    _In_opt_ LPCVOID lpSource,
    _In_     DWORD dwMessageId,
    _In_     DWORD dwLanguageId,
    _When_((dwFlags & FORMAT_MESSAGE_ALLOCATE_BUFFER) != 0, _At_((LPSTR*)lpBuffer, _Outptr_result_z_))
    _When_((dwFlags & FORMAT_MESSAGE_ALLOCATE_BUFFER) == 0, _Out_writes_z_(nSize))
             LPSTR lpBuffer,
    _In_     DWORD nSize,
    _In_opt_ va_list *Arguments
    );

2>c:\thirdparty\source\boost\boost_1_71_0\boost\winapi\error_handling.hpp(25): error C28251: Inconsistent annotation for 'FormatMessageA': this instance has no annotations. See c:\program files (x86)\windows kits\10\include\10.0.17134.0\um\winbase.h(2387).

[Riadela]

I also get this unusual warning .. which it seems I'm the only one in the web

c:\thirdparty\source\boost\boost_1_71_0\boost\math\special_functions\next.hpp(502): error C6031: Return value ignored: 'frexp'.

[Lastique]

The math one is not related to Boost.WinAPI. You can report it to Boost.Math.

The other warnings seem to be caused by returned value and argument check attributes. I won't be adding those because different Windows SDKs use different markup for those. I recommend you disabling the warning. I'll probably disable it in the future with a pragma.