When using MSVC to compile v12.1.0, still many compilation warnings are generated

[EvgeniyITCS]

Related to: #4565

size_t and unsigned __int64 do not match when compiling with MSVC x86, resulting in the compiler generating warnings. It is build failure if compiler setted to treat warnings as error.

[19:25:29] : [Python run] C:\Users\ContainerAdministrator\7e1acc4fec462\p\include\fmt/format.h(2537): error C2220: the following warning is treated as an error
[19:25:29] : [Python run] C:\Users\ContainerAdministrator\7e1acc4fec462\p\include\fmt/format.h(2537): warning C4244: 'argument': conversion from 'unsigned __int64' to 'size_t', possible loss of data

...

[19:25:29] : [Python run] C:\Users\ContainerAdministrator\7e1acc4fec462\p\include\fmt/format.h(2553): warning C4244: 'argument': conversion from 'unsigned __int64' to 'size_t', possible loss of data
[19:25:29] : [Python run] C:\Users\ContainerAdministrator\7e1acc4fec462\p\include\fmt/format.h(2599): warning C4244: 'argument': conversion from 'unsigned __int64' to 'size_t', possible loss of data

...

[19:25:29] : [Python run] C:\Users\ContainerAdministrator\7e1acc4fec462\p\include\fmt/format.h(2600): warning C4244: 'argument': conversion from 'unsigned __int64' to 'size_t', possible loss of data

[vitaut]

Thanks for reporting but fixing all possible warnings (especially MSVC level 4 which are mostly noise) is a non-goal.

[DHowett]

Unfortunately, this specific set of warnings also causes a build failure with FMT_PEDANTIC=ON. I know that it may not be a project goal to support /W4, but on MSVC, C4244 is part of /W3 (!) and in some places /W3 is a mandatory compiler flag. FMT_PEDANTIC being an option seems to suggest that it should be supported as project goal. ☹️

(Also, other locations around the narrowing warnings do static_cast<size_t>... so it is not unheard-of. :))

[DHowett]

However, it looks like this was already fixed with #4594!