assert: Support types without operator== (int) [BZ #21972]

1 files changed, 10 insertions, 6 deletions

diff --git a/assert/assert.h b/assert/assert.h
index 6801cfeb10..640c95c063 100644
--- a/assert/assert.h
+++ b/assert/assert.h
@@ -85,7 +85,12 @@ __END_DECLS
 /* When possible, define assert so that it does not add extra
    parentheses around EXPR.  Otherwise, those added parentheses would
    suppress warnings we'd expect to be detected by gcc's -Wparentheses.  */
-# if !defined __GNUC__ || defined __STRICT_ANSI__
+# if defined __cplusplus
+#  define assert(expr)							\
+     (static_cast <bool> (expr)						\
+      ? void (0)							\
+      : __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
+# elif !defined __GNUC__ || defined __STRICT_ANSI__
 #  define assert(expr)							\
     ((expr)								\
      ? __ASSERT_VOID_CAST (0)						\
@@ -93,12 +98,11 @@ __END_DECLS
 # else
 /* The first occurrence of EXPR is not evaluated due to the sizeof,
    but will trigger any pedantic warnings masked by the __extension__
-   for the second occurrence.  The explicit comparison against zero is
-   required to support function pointers and bit fields in this
-   context, and to suppress the evaluation of variable length
-   arrays.  */
+   for the second occurrence.  The ternary operator is required to
+   support function pointers and bit fields in this context, and to
+   suppress the evaluation of variable length arrays.  */
 #  define assert(expr)							\
-  ((void) sizeof ((expr) == 0), __extension__ ({			\
+  ((void) sizeof ((expr) ? 1 : 0), __extension__ ({			\
       if (expr)								\
         ; /* empty */							\
       else								\