use std namespace for int types under cstdint

[UnixY2K]

integer types under cstdint are only required to be under the std namespace while the global namespace definition is optional.

this PR fixes the undefined behavior for the files that assume global namespace availability.

[GuillaumeDua]

LGTM 👍 Thanks

[dvtate]

Maybe there's something I'm missing but if std::int32_t doesn't alias the same type as int32_t there's something seriously wrong with your compiler's copy of the standard library or you're doing something very sketchy ... either way, library maintainers shouldn't try to work around that IMO.

[GuillaumeDua]

@dvtate I can't see anything exotic about the toolchain. Clang-21 with libstdc++.

Already saw such an issue in the past on other projects over the last perhaps 10+ years,
the reliable solution was always to use #include <cstdint> and std::int32_t.

But yeah, this is frustrating to not pin-point the root cause.

[dvtate]

I'm not seeing that in clang 21 (or any compiler for that matter).

Please find a compiler where this doesn't compile: https://godbolt.org/z/4GvEqbGze (for older compilers you may need --std=c++11 ).

According to chatgpt the only time that they wouldn't be the same is if that platform doesn't have a 32 bit integer type (unrealistic), in which case std::int32_t wouldn't exist and you'd get a compiler error if you tried to use it.

[GuillaumeDua]

@dvtate Did you try with the information provided in the issue ? #535 (comment)

Sadly, I don't have time for futher investigation.
So if you want to downvote or block this PR, then the choice is yours.

As mentioned, it's already fixed in 3.3.3 anyway.