N4100 states that an error shall be reported if
`!exists(p) || !is_directory(p)`. We were missing the first half of the
conditional. Invert the error and normal code paths to make the code
easier to follow.
llvm-svn: 294127
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'.
llvm-svn: 273034
Saleem Abdulrasool