ignore-value: revert previous code change

[gnulib.git] / lib / ignore-value.h

diff --git a/lib/ignore-value.h b/lib/ignore-value.h
index ebd6bf4..633c44a 100644 (file)
--- a/lib/ignore-value.h
+++ b/lib/ignore-value.h
@@ -35,9 +35,11 @@
 #ifndef _GL_IGNORE_VALUE_H
 #define _GL_IGNORE_VALUE_H
 
-/* The __attribute__((__warn_unused_result__)) feature
-   is available in gcc versions 3.4 and newer,
-   while the typeof feature has been available since 2.7 at least.  */
+/* 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.  */
 #if 3 < __GNUC__ + (4 <= __GNUC_MINOR__)
 # define ignore_value(x) \
     (__extension__ ({ __typeof__ (x) __x = (x); (void) __x; }))