llvm-project/libcxx
Eric Fiselier a9e659619f Implement N4606 optional
Summary:
Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional.

  - Update relational operators per http://wg21.link/P0307
  - Update to requirements of http://wg21.link/P0032
  - Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable.

Audit P/Rs for optional LWG issues:
  - 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R).
  - 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression.
  - 2740 "constexpr optional<T>::operator->" Already conforming.
  - 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented.
  - 2748 "swappable traits for optionals" Already conforming.
  - 2753 "Optional's constructors and assignments need constraints" Implemented.

Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey!



Reviewers: mclow.lists, CaseyCarter, EricWF

Differential Revision: https://reviews.llvm.org/D22741

llvm-svn: 283980
2016-10-12 07:46:20 +00:00
..
benchmarks Cleanup CMake status output 2016-10-10 06:31:00 +00:00
cmake Cleanup CMake status output 2016-10-10 06:31:00 +00:00
docs Make it easier to run the libc++ test suite against libstdc++ 2016-10-12 00:00:37 +00:00
include Implement N4606 optional 2016-10-12 07:46:20 +00:00
lib Fix linker script generation for in-tree builds 2016-10-09 21:34:03 +00:00
src Implement N4606 optional 2016-10-12 07:46:20 +00:00
test Implement N4606 optional 2016-10-12 07:46:20 +00:00
utils Remove debug output from gen_linker_script.py 2016-10-09 21:43:30 +00:00
www Fix LWG2683 - filesystem::copy() should always clear the user-provided error_code 2016-10-11 22:18:09 +00:00
.arcconfig Upgrade arcconfig to use https 2016-07-18 02:02:49 +00:00
.gitignore Implement N4606 optional 2016-10-12 07:46:20 +00:00
CMakeLists.txt Fix documentation mis-spelling. 2016-10-10 14:45:06 +00:00
CREDITS.TXT Add entry to CREDITS.TXT for propagate_const 2016-06-19 19:36:28 +00:00
LICENSE.TXT Update copyright year to 2016. 2016-03-30 22:39:53 +00:00
TODO.TXT Remove out of date items in TODO.txt 2016-09-27 01:28:47 +00:00