Cannot build on Windows with Visual Studio

[degloff]

I wonder what is wrong here

// without this defined it does not build 
#define _SILENCE_ALL_MS_EXT_DEPRECATION_WARNINGS

#include "spdlog/spdlog.h"

int main()
{
    std::string a = "abc";
    std::string b = "123";
    
    spdlog::debug("a={}, b={}", a, b);

    SPDLOG_DEBUG("Some debug message");
}

If I remove #define _SILENCE_ALL_MS_EXT_DEPRECATION_WARNINGS I get the following error

1>test_spdlog.cpp
1>xxx\spdlog\fmt\bundled\format.h(490,51): error C4996: 'stdext::checked_array_iterator<_Ty*>': warning STL4043: stdext::checked_array_iterator, stdext::unchecked_array_iterator, and related factory functions are non-Standard extensions and will be removed in the future. std::span (since C++20) and gsl::span can be used instead. You can define _SILENCE_STDEXT_ARR_ITERS_DEPRECATION_WARNING or _SILENCE_ALL_MS_EXT_DEPRECATION_WARNINGS to suppress this warning.
1>(compiling source file 'test_spdlog.cpp')
1>C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.38.33130\include\iterator(1470,1):
1>see declaration of 'stdext::checked_array_iterator'
1>xxx\spdlog\fmt\bundled\format.h(493,3): error C4996: 'stdext::checked_array_iterator<T *>::checked_array_iterator': warning STL4043: stdext::checked_array_iterator, stdext::unchecked_array_iterator, and related factory functions are non-Standard extensions and will be removed in the future. std::span (since C++20) and gsl::span can be used instead. You can define _SILENCE_STDEXT_ARR_ITERS_DEPRECATION_WARNING or _SILENCE_ALL_MS_EXT_DEPRECATION_WARNINGS to suppress this warning.
1>xxx\spdlog\fmt\bundled\format.h(493,3): error C4996:         with
1>xxx\spdlog\fmt\bundled\format.h(493,3): error C4996:         [
1>xxx\spdlog\fmt\bundled\format.h(493,3): error C4996:             T=fmt::v9::detail::bigint::bigit
1>xxx\spdlog\fmt\bundled\format.h(493,3): error C4996:         ]
1>(compiling source file 'test_spdlog.cpp')
1>xxx\spdlog\fmt\bundled\format.h(493,3):
1>the template instantiation context (the oldest one first) is
1>	xxx\spdlog\fmt\bundled\format.h(2807,34):
1>	see reference to function template instantiation 'stdext::checked_array_iterator<T *> fmt::v9::detail::make_checked<T>(T *,size_t)' being compiled
1>        with
1>        [
1>            T=fmt::v9::detail::bigint::bigit
1>        ]

I tried with all the language version C++14 to C++20. Do I use spdlog in a wrong way? I use the header only version which I cloned directly from Github.

[tt4g]

Duplicate #2987 and already fixed fmtlib/fmt#3540.
If you define _SILENCE_ALL_MS_EXT_DEPRECATION_WARNINGS, you should also define CMake variable SPDLOG_FMT_EXTERNAL and use external fmt.