[Bug libstdc++/99876] std::filesystem::absolute is inefficient

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99876

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-04-01
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to M Welinder from comment #0)
> If the given filename is already absolute, it should be simply returned.
> There is no need to call current_path() which leads to a getcwd syscall.

Yes we already do that for the overload with an error_code parameter:

fs::path
fs::absolute(const path& p, error_code& ec)
{
  path ret;
  if (p.empty())
    {
      ec = make_error_code(std::errc::invalid_argument);
      return ret;
    }
  ec.clear();
  if (p.is_absolute())
    {
      ret = p;
      return ret;
    }