That's my point - GSL is NOT MSVC only, it's a general purpose library and NOT a standard library implementation of a toolchain so any compiler is expected to be able to compile it (it also explicitly targets clang & gcc).
replyIt was originally created by Microsoft and as Herb mentions "all our target platforms", so most likely it gets special treatment.
replyAt the time Herb made that comment GSL was documented as supporting XCode 12.5.1/13.2.1, GCC 10/11, Clang 11/12, and Visual Studio 2019/2022 using both MSVC/LLVM [0]. Even if MSVC had special support for GSL I'm a bit more skeptical that such support would extend to XCode, GCC, and Clang.
reply[0]: https://github.com/microsoft/GSL/tree/99a29ce797c8337b8923f2...
GSL is not the standard library nor an internal runtime library. Its GitHub page claims that it supports a variety of compilers:
reply> The GSL officially supports recent major versions of Visual Studio with both MSVC and LLVM, GCC, Clang, and XCode with Apple-Clang
It was originally created by Microsoft and as Herb mentions "all our target platforms", so most likely it gets special treatment.
replyThere is absolutely no special treatment afforded to the GSL by any of the target platforms. While we can't inspect MSVC's source code, both clang and GCC do not have any support or affordance for the GSL whatsoever and it would be very unusual to expect MSVC's source code to have some kind of affordance for this library.
replyThe 'special treatment' isn't technical, it's procedural -- insofar as if, during development for a new release, MSVC were to land some changes that broke GSL, Microsoft's testing would catch that and ensure that the changes were reverted or fixed to support the latter, prior to shipping. Since they're built as part of the same operating system, they can make sure not to step on one another's toes -- which is not a guarantee that they can make to third-party applications.
replyIf you've ever read anything about the internal culture in Microsoft, you'd know this is extremely implausible.
replyI have no idea where you possibly got this idea from since the Github Issues tracker for GSL has numerous instances of new releases of MSVC breaking GSL compilation.
replyClang is a target for the GSL though. How can MSVC's special powers prevent this from being exploitable UB in Clang/LLVM?
replyThis code boils down to static_cast<int>(some_double); so nothing fancy is going on here
Actually Microsoft has their own fork that ships with Visual Studio installer.
replyHowever that was me guessing from Herb Sutter's reply.