Eric Fiselier e7f8cd476d [libc++] Shrink variant's index type when possible ...

Summary:
Currently `std::variant` always uses an unsigned int to store the variant index. However this isn't nessesary and causes `std::variant` to be larger than it needs to be in most cases.

This patch changes the index type to be `unsigned char` when possible, and `unsigned short` or `unsigned int` otherwise, depending on the size (Although it's questionable if it's even possible to create a variant with 65535 elements.

Unfortunately this change is an ABI break, and as such is only enabled in ABI v2.

Reviewers: mpark

Reviewed By: mpark

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D40210

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@318621 91177308-0d34-0410-b5e6-96231b3b80d8

2017-11-19 04:19:44 +00:00

..

libcxx

[libc++] Shrink variant's index type when possible

2017-11-19 04:19:44 +00:00

std

More of P0600 - '[[nodiscard]] in the Library' mark empty() as nodiscard in filesystem::path

2017-11-16 05:48:32 +00:00

support

Rename identifiers named __output

2017-11-14 11:14:25 +00:00

CMakeLists.txt

Resubmit "Fix llvm-lit script generation in libcxx."

2017-09-19 17:19:10 +00:00

lit.cfg

Move libcxx/test/libcxx python package into libcxx/utils/libcxx.

2017-02-09 23:18:11 +00:00

lit.site.cfg.in

[libc++][CMake] Use debug MSVC runtimes when libc++ is built in debug mode

2017-01-14 07:54:39 +00:00

nothing_to_do.pass.cpp

Test commit: Reverting whitespace changes

2014-07-17 05:10:03 +00:00