Imported Upstream version 1.4

[debian/gzip] / lib / ignore-value.h

diff --git a/lib/ignore-value.h b/lib/ignore-value.h
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+/* ignore a function return without a compiler warning
+
+   Copyright (C) 2008-2010 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering.  */
+
+/* Use these functions 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".  */
+
+static inline void ignore_value (int i) { (void) i; }
+static inline void ignore_ptr (void* p) { (void) p; }
+/* FIXME: what about aggregate types? */