[PATCH v1 0/4] Implement extents from the mdspan header.

[Luc Grosheintz]

The `v1` in the subject line is a copy-paste error while
creating the subject line.

This is the preceding patch series:
https://gcc.gnu.org/pipermail/libstdc++/2025-April/060988.html

On 4/17/25 1:16 PM, Luc Grosheintz wrote:
> The following changes were made since v2:
> * Implement the missing part of the class mandates.
> * Combined more test cases into a smaller number of files.
> * Changed constexpr checks as requested.
> * Small improvements to the test rigour.
> * Several cosmetic changes requested during review.
> 
> The first two patches of the series haven't changed since v2.
> 
> Luc Grosheintz (4):
>    libstdc++: Setup internal FTM for mdspan.
>    libstdc++: Add header mdspan to the build-system.
>    libstdc++: Implement std::extents [PR107761].
>    libstdc++: Add tests for std::extents.
> 
>   libstdc++-v3/doc/doxygen/user.cfg.in          |   1 +
>   libstdc++-v3/include/Makefile.am              |   1 +
>   libstdc++-v3/include/Makefile.in              |   1 +
>   libstdc++-v3/include/bits/version.def         |   9 +
>   libstdc++-v3/include/bits/version.h           |   9 +
>   libstdc++-v3/include/precompiled/stdc++.h     |   1 +
>   libstdc++-v3/include/std/mdspan               | 297 ++++++++++++++++++
>   libstdc++-v3/src/c++23/std.cc.in              |   6 +-
>   .../23_containers/mdspan/extents/ctor_copy.cc |  82 +++++
>   .../23_containers/mdspan/extents/ctor_ints.cc |  62 ++++
>   .../mdspan/extents/ctor_shape.cc              | 160 ++++++++++
>   .../mdspan/extents/custom_integer.cc          |  87 +++++
>   .../23_containers/mdspan/extents/misc.cc      | 223 +++++++++++++
>   13 files changed, 938 insertions(+), 1 deletion(-)
>   create mode 100644 libstdc++-v3/include/std/mdspan
>   create mode 100644 libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_copy.cc
>   create mode 100644 libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_ints.cc
>   create mode 100644 libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_shape.cc
>   create mode 100644 libstdc++-v3/testsuite/23_containers/mdspan/extents/custom_integer.cc
>   create mode 100644 libstdc++-v3/testsuite/23_containers/mdspan/extents/misc.cc
>