[libc++] Fix PR34898 - vector iterator constructors and assign method perform push_back instead of emplace_back.
Summary:
The constructors `vector(Iter, Iter, Alloc = Alloc{})` and `assign(Iter, Iter)` don't correctly perform EmplaceConstruction from the result of dereferencing the iterator. This results in them performing an additional and unneeded copy.
This patch addresses the issue by correctly using `emplace_back` in C++11 and newer.
There are also some bugs in our `insert` implementation, but those will be handled separately.
@mclow.lists We should probably merge this into 5.1, agreed?
Reviewers: mclow.lists, dlj, EricWF
Reviewed By: mclow.lists, EricWF
Subscribers: cfe-commits, mclow.lists
Differential Revision: https://reviews.llvm.org/D38757
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@315994 91177308-0d34-0410-b5e6-96231b3b80d8
12 files changed
