what runtime is used here?

[3052]

currently I am using https://github.com/mstorsjo/llvm-mingw, which offers both UCRT and MSVCRT

https://github.com/mstorsjo/llvm-mingw/releases

what is offered here?

MSVCRT. There is no UCRT.

[Peter0x44]

He is correct. The answer to "What runtime is used here (by w64devkit)?" is MSVCRT.

There is no official UCRT build of w64devkit.

Curious what your use case is to need it.

[skeeto]

As usual for engineering decisions there are trade-offs, and UCRT has its own costs. So, no, it's not obviously better because w64dk wouldn't work nearly as well with UCRT. Namely, UCRT is strictly Windows 10† and later, while w64dk supports XP and later. I'm aware of only three benefits of UCRT over Mingw-w64-enhanced MSVCRT: 1. UCRT abort/assert breaks in debuggers rather than ambiguously exits. (Like printf, I expect this could be fixed for MSVCRT in Mingw-w64.) 2. UCRT atof can parse "nan" (#98). (This could definitely be fixed for MSVCRT in Mingw-w64 with a small patch.) 3. Static linking with objects compiled against UCRT by other toolchains, such as Visual Studio. (Dynamic linking across toolchains has always worked.) Like MSVCRT, UCRT is a mediocre implementation of the C standard library (and MS-specific extensions), which is itself mostly useless for modern software (null terminated strings, etc.). Well-written programs rely on these CRTs too little distinguish to between them, so MSVCRT is obviously better suited for w64dk due to its better compatibility. (Some programs included in w64dk use no CRT at all, making this irrelevant anyway.) If you're writing "Modern C++" you definitely won't notice the difference. † The documentation suggests there's a redistributable URCT package for Windows 7 but even if it worked, which it doesn't, it's impractical.

[3052]

So, no, it's not obviously better because w64dk wouldn't work nearly as well with UCRT.

@skeeto thanks for the reply, but I never said UCRT was better, I just recognize that two options are available so I wanted to see which ones were offered here. I was not making a judgement between the two options

[stianhoiland]

@3052 wrote:

this is obviously wrong
<link...>

Did you mean that the info at the link is obviously wrong?

[3052]

this is vague:

There is no UCRT.

because in the general context its wrong, which I was pointing out. he should have said:

There is no UCRT w64devkit

[Peter0x44]

Just to add a little bit of info about the compatibility, since Microsoft document this so poorly.

Static linking UCRT actually works on Windows XP (SP3?) (including the utf8 codepage), but MSVC is the only toolchain capable of doing this.