[all-commits] [llvm/llvm-project] 0fa118: Add default initialization to compressed_pair.

[Eric via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 0fa118a9da6786a0aaf81e309d8c3b38bc5f61dd
      https://github.com/llvm/llvm-project/commit/0fa118a9da6786a0aaf81e309d8c3b38bc5f61dd
  Author: Eric Fiselier <eric at efcs.ca>
  Date:   2019-12-16 (Mon, 16 Dec 2019)

  Changed paths:
    M libcxx/include/memory
    A libcxx/test/libcxx/memory/compressed_pair/compressed_pair.pass.cpp

  Log Message:
  -----------
  Add default initialization to compressed_pair.

This change introduces the __default_init_tag to memory, and a corresponding
element constructor to allow for default initialization of either of the pair
values. This is useful for classes such as std::string where most (all)
constructors explicitly initialize the values in the constructor.

Patch by Martijn Vels (mvels at google.com)
Reviewed as https://reviews.llvm.org/D70617