[PATCH v3] libstdc++: Mark <queue>, <deque> constexpr

[Yuao Ma]

On Wed, Aug 19, 2026 at 7:07 PM Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Thu, 06 Aug 2026 at 19:51 +0800, Yuao Ma wrote:
> >Looking forward to this! Just a quick question, does this patch
> >resolve the error in https://compiler-explorer.com/z/39MsxKxTT ?
>
> The -fimplicit-constexpr option only works for inline functions. Since
> that function is not inline, you can't make it a constexpr function by
> using -fimplicit-constexpr:
>
>    template<typename _Tp, typename _Alloc>
>      void
>      _Deque_base<_Tp, _Alloc>::
>      _M_initialize_map(size_t __num_elements)
>
> Because the patch makes everything explicitly constexpr, of course it
> resolves that error.
>

Thanks for the explanation! In this case I think maybe there is no
major blocker for p3372r2. Glad to help implement unfinished ones.