bool is_symlink(file_status s) noexcept;
bool is_symlink(const path& p);
bool is_symlink(const path& p, error_code& ec) noexcept;
Returns: is_symlink(symlink_status(p)) or is_symlink(symlink_status(p, ec)), respectively. The signature with argument ec returns false if an error occurs.
Throws: As specified in [fs.err.report].