Fix LWG issue 2469 - Use piecewise construction in unordered_map::operator.
unordered_map's allocator may only be used to construct objects of 'value_type',
or in this case 'pair<const Key, Value>'. In order to respect this requirement
in operator, which requires default constructing the 'mapped_type', we have
to use pair's piecewise constructor with '(tuple<Kep>, tuple<>)'.
Unfortunately we still need to provide a fallback implementation for C++03
since we don't have <tuple>. Even worse this fallback is the last remaining
user of '__hash_map_node_destructor' and '__construct_node_with_key'.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260601 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed