bool is_fifo(file_status s) noexcept;
Returns: s.type() == file_type::fifo. bool is_fifo(const path& p);
bool is_fifo(const path& p, error_code& ec) noexcept;
Returns: is_fifo(status(p)) or
is_fifo(status(p, ec)), respectively
. The signature with argument
ec returns
false if an error occurs
.