LWG 3013 points out that the constructors and increment members
of the directory iterators need to allocate, and therefore cannot
be marked noexcept.
It also points out that `is_empty` and `copy` likely need to allocate
as well, and as such can also not be noexcept.
This patch speculatively implements the resolution removing noexcept,
because libc++ does indeed have the possibility of throwing on allocation
failure.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@316941 91177308-0d34-0410-b5e6-96231b3b80d8
Add the completed std::experimental::filesystem implementation and tests.
The implementation supports C++11 or newer.
The TS is built as part of 'libc++experimental.a'. Users of the TS need to
manually link this library. Building and testing the TS can be disabled using
the CMake option '-DLIBCXX_ENABLE_FILESYSTEM=OFF'.
Currently 'libc++experimental.a' is not installed by default. To turn on the
installation of the library use '-DLIBCXX_INSTALL_EXPERIMENTAL_LIBRARY=ON'.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@273034 91177308-0d34-0410-b5e6-96231b3b80d8
