[libcxx-dev] Status of P0645 (std::format) in libc++

Mark de Wever via libcxx-dev libcxx-dev at lists.llvm.org
Sat May 15 04:09:51 PDT 2021

Hi Spencer,

On Sat, May 15, 2021 at 11:15:51AM +0100, Spencer Collyer via libcxx-dev wrote:
> I'm wondering what the status of P0645 in libc++ is at the moment?
> This is the proposal that introduces the std::format text formatting
> library in C++20.
> I've checked the page https://libcxx.llvm.org/docs/Cxx2aStatus.html
> and it says that it 'In Progress'. Is there any indication when it
> will be available?

There's a dedicated page containing the detailed implementation status
of std::format [1]. 

There are some patches in libc++, but nothing useful yet.

I've been working on std::format in a private branch. At the moment I'm
polishing these patches and I expect to put them up for review this
month. These patches implement formatting for:
- string
- bool
- char
- integer

I hope to land these patches to before libc++13. I hope to get more done
in the libc++13 time-frame, but that depends on how much time I've
available. Floating-point support is unlikely to make it; it depends on
std::to_chars for floating-point. There's a review, but I need to find
the time to pick it up again.

I expect libc++14 to complete the std::format papers. I'm not sure
when std::chrono support will be available. I haven't looked at the
C++20 implementation status of std::chrono yet.

[1] https://libcxx.llvm.org/docs/FormatStatus.html

Kind regards,
Mark de Wever

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