[Bug libstdc++/108952] Regression in uses_allocator_construction_args for pair of rvalue references

[pdimov at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108952

Peter Dimov <pdimov at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |pdimov at gmail dot com

--- Comment #4 from Peter Dimov <pdimov at gmail dot com> ---
An easy fix is to use `std::get<0>` instead of `.first`.