[Bug libstdc++/71044] Optimize std::filesystem implementation

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71044

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Sat Feb  9 00:25:39 2019
New Revision: 268713

URL: https://gcc.gnu.org/viewcvs?rev=268713&root=gcc&view=rev
Log:
Add noexcept to filesystem::path query functions

In the standard these member functions are specified in terms of the
potentially-throwing path decompositions functions, but we implement
them without constructing any new paths or doing anything else that can
throw.

        PR libstdc++/71044
        * include/bits/fs_path.h (path::has_root_name)
        (path::has_root_directory, path::has_root_path)
        (path::has_relative_path, path::has_parent_path)
        (path::has_filename, path::has_stem, path::has_extension)
        (path::is_absolute, path::is_relative, path::_M_find_extension): Add
        noexcept.
        * src/c++17/fs_path.cc (path::has_root_name)
        (path::has_root_directory, path::has_root_path)
        (path::has_relative_path, path::has_parent_path)
        (path::has_filename, path::_M_find_extension): Add noexcept.

Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/bits/fs_path.h
    trunk/libstdc++-v3/src/c++17/fs_path.cc