[Bug libstdc++/101722] [12 Regression] The recently change seems to break existing code

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101722

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
/home/jwakely/gcc/12/include/c++/12.0.0/utility: In function '_Tp
boost::math::tools::meta_programming::std::exchange(_Tp&, _Up&&)':
/home/jwakely/gcc/12/include/c++/12.0.0/utility:94:19: error: '__exchange' is
not a member of 'boost::math::tools::meta_programming::std'; did you mean
'exchange'?
   94 |     { return std::__exchange(__obj, std::forward<_Up>(__new_val)); }
      |                   ^~~~~~~~~~
      |                   exchange


The namespace nesting is messed up.