Cannot build with msvc2019 and flag ''/std:c++17"

Describe the bug Cannot build with msvc2019 and flag ''/std:c++17". I will submit a pull request very soon.

Got the following error:

...\MSVC\1416~1.270\bin\HostX64\x64\cl.exe /TP -IC:\dfir-orc\external\vcpkg\buildtrees\stx\src\v1.0.1-4b75bce9d4\include /nologo /DWIN32 /D_WINDOWS /W3 /utf-8 /GR /EHsc /MP /std:c++17 /D_SILENCE_ALL_CXX17_DEPRECATION_WARNINGS /D_DEBUG /MTd /Z7 /Ob0 /Od /RTC1 /W4 -std:c++17 /showIncludes /FoCMakeFiles\stx.dir\src\panic\hook.cc.obj /FdCMakeFiles\stx.dir\stx.pdb /FS -c C:\dfir-orc\external\vcpkg\buildtrees\stx\src\v1.0.1-4b75bce9d4\src\panic\hook.cc
cl : Command line warning D9025 : overriding '/W3' with '/W4'
...\include\stx/config.h(245): warning C4067: unexpected tokens following preprocessor directive - expected a newline
...\include\stx/config.h(261): warning C4067: unexpected tokens following preprocessor directive - expected a newline
...\include\stx/config.h(262): fatal error C1189: #error: C++ attribute nodiscard is not available on this compiler. Important unused function results will not raise a warning. Please upgrade to a newer version.
ninja: build stopped: subcommand failed.

Expected behavior Everything builds correctly without the check made on config.h. The __has_cpp_attribute used below in config.h does not seem to be available.

#if !__has_cpp_attribute(nodiscard)
#error C++ attribute `nodiscard` is not available on this compiler. Important unused function results will not raise a warning. Please upgrade to a newer version.
#endif

#if !__has_cpp_attribute(deprecated)
#error C++ attribute `deprecated` is not available on this compiler. Please upgrade to a newer version.
#endif

#if !__has_cpp_attribute(noreturn)
#error C++ function attribute `noreturn` is not available on this compiler. Please upgrade to a newer version.
#endif

Desktop (please complete the following information):

OS: Windows10
Visual Studio 2019 (16.6.2)

lamarrr / STX

Cannot build with msvc2019 and flag ''/std:c++17" #10