pmt: revert 7f8090b

include/libgnulib/ignore-value.h

@@ -1,51 +0,0 @@
-/* ignore a function return without a compiler warning.  -*- coding: utf-8 -*-
-
-   Copyright (C) 2008-2024 Free Software Foundation, Inc.
-
-   This file is free software: you can redistribute it and/or modify
-   it under the terms of the GNU Lesser General Public License as
-   published by the Free Software Foundation; either version 2.1 of the
-   License, or (at your option) any later version.
-
-   This file is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public License
-   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
-
-/* Written by Jim Meyering, Eric Blake and Pádraig Brady.  */
-
-/* Use "ignore_value" to avoid a warning when using a function declared with
-   gcc's warn_unused_result attribute, but for which you really do want to
-   ignore the result.  Traditionally, people have used a "(void)" cast to
-   indicate that a function's return value is deliberately unused.  However,
-   if the function is declared with __attribute__((warn_unused_result)),
-   gcc issues a warning even with the cast.
-
-   Caution: most of the time, you really should heed gcc's warning, and
-   check the return value.  However, in those exceptional cases in which
-   you're sure you know what you're doing, use this function.
-
-   For the record, here's one of the ignorable warnings:
-   "copy.c:233: warning: ignoring return value of 'fchown',
-   declared with attribute warn_unused_result".  */
-
-#ifndef _GL_IGNORE_VALUE_H
-#define _GL_IGNORE_VALUE_H
-
-/* Normally casting an expression to void discards its value, but GCC
-   versions 3.4 and newer have __attribute__ ((__warn_unused_result__))
-   which may cause unwanted diagnostics in that case.  Use __typeof__
-   and __extension__ to work around the problem, if the workaround is
-   known to be needed.
-   The workaround is not needed with clang.  */
-#if (3 < __GNUC__ + (4 <= __GNUC_MINOR__)) && !defined __clang__
-# define ignore_value(x) \
-    (__extension__ ({ __typeof__ (x) __x = (x); (void) __x; }))
-#else
-# define ignore_value(x) ((void) (x))
-#endif
-
-#endif