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imneme / pcg-cpp

PCG — C++ Implementation
Apache License 2.0
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Make engine constexpr under c++14 and higher #75

Open MBalszun opened 2 years ago

MBalszun commented 2 years ago

Would you be interested in a PR that makes most functions of this library constexpr? I haven't really investigated this yet, but it seems that one could just slab a CONSTEXPR_IN_ CPP14 -style macro in front of most functions. The only tricky bit would be to make sure that this macro is restrictive enough that it doesn't accidentally add constexpr for a compiler / c++ version combination that nominally supports e.g. c++14 constexpr, but actually has an incomplete implementation which then results in a compilation error even when the function isn't used in a constexpr context.

timoscs commented 11 months ago

@MBalszun a potentially useful hint, if you ever get around to working on such a PR: you can't make seed constexpr as-is under anything less than C++20, since it uses placement new internally (in C++20, you can use std::construct_at which does the trick).

I know this because I'm using my own fork under C++20 and wanted constexpr functionality, but I did that without macros and tested only on GCC12 so it's not directly useful for what you're suggesting.

MBalszun commented 6 months ago

@timoscs: Thanks for the hint. However, I got the impression, this repo is no longer maintained anyway and I don't see any option to open PRs.

imneme commented 6 months ago

To answer the original question, yes, I'd be interested. There is something to be said for having backwards compatibility to older versions of C++, but supporting constexpr use would be a valuable feature.