On Thu, 21 Oct 2021 at 15:38, Patrick Palka via Libstdc++ <
libstd...@gcc.gnu.org> wrote:
> Tested on x86_64-pc-linux-gnu, does this look ok for trunk/11/10?
>
Yes to all, thanks.
> PR libstdc++/102358
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/stl_iterator.h (__niter_base): Make constexpr
> for C++20.
> (__miter_base): Likewise.
> * testsuite/25_algorithms/move/constexpr.cc: New test.
> ---
> libstdc++-v3/include/bits/stl_iterator.h | 2 ++
> .../testsuite/25_algorithms/move/constexpr.cc | 19 +++++++++++++++++++
> 2 files changed, 21 insertions(+)
> create mode 100644 libstdc++-v3/testsuite/25_algorithms/move/constexpr.cc
>
> diff --git a/libstdc++-v3/include/bits/stl_iterator.h
> b/libstdc++-v3/include/bits/stl_iterator.h
> index 8afd6756613..fbd91956ced 100644
> --- a/libstdc++-v3/include/bits/stl_iterator.h
> +++ b/libstdc++-v3/include/bits/stl_iterator.h
> @@ -2470,6 +2470,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> /// @} group iterators
>
> template<typename _Iterator>
> + _GLIBCXX20_CONSTEXPR
> auto
> __niter_base(move_iterator<_Iterator> __it)
> -> decltype(make_move_iterator(__niter_base(__it.base())))
> @@ -2483,6 +2484,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> };
>
> template<typename _Iterator>
> + _GLIBCXX20_CONSTEXPR
> auto
> __miter_base(move_iterator<_Iterator> __it)
> -> decltype(__miter_base(__it.base()))
> diff --git a/libstdc++-v3/testsuite/25_algorithms/move/constexpr.cc
> b/libstdc++-v3/testsuite/25_algorithms/move/constexpr.cc
> new file mode 100644
> index 00000000000..773c55cfb50
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/25_algorithms/move/constexpr.cc
> @@ -0,0 +1,19 @@
> +// { dg-options "-std=gnu++20" }
> +// { dg-do compile { target c++20 } }
> +
> +#include <algorithm>
> +#include <span>
> +
> +constexpr bool
> +test01()
> +{
> + // PR libstdc++/102358
> + int x[2] = {1,2}, y[2];
> + std::span in(x), out(y);
> + std::move(std::move_iterator(in.begin()), std::move_iterator(in.end()),
> + out.begin());
> + return std::equal(std::move_iterator(in.begin()),
> std::move_iterator(in.end()),
> + std::move_iterator(out.begin()));
> +}
> +
> +static_assert(test01());
> --
> 2.33.1.711.g9d530dc002
>
>
