alignof: Avoid collision with stdalign module.

[gnulib.git] / lib / alignof.h

diff --git a/lib/alignof.h b/lib/alignof.h
index 9b8e00d..bff3930 100644 (file)
--- a/lib/alignof.h
+++ b/lib/alignof.h
@@ -20,8 +20,11 @@
 
 #include <stddef.h>
 
-/* Determine the alignment of a structure slot (field) of a given type,
+/* alignof_slot (TYPE)
+   Determine the alignment of a structure slot (field) of a given type,
    at compile time.  Note that the result depends on the ABI.
+   This is the same as alignof (TYPE) and _Alignof (TYPE), defined in
+   <stdalign.h> if __alignof_is_defined is 1.
    Note: The result cannot be used as a value for an 'enum' constant,
    due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc.  */
 #if defined __cplusplus
@@ -31,7 +34,8 @@
 # define alignof_slot(type) offsetof (struct { char __slot1; type __slot2; }, __slot2)
 #endif
 
-/* Determine the good alignment of an object of the given type at compile time.
+/* alignof_type (TYPE)
+   Determine the good alignment of an object of the given type at compile time.
    Note that this is not necessarily the same as alignof_slot(type).
    For example, with GNU C on x86 platforms: alignof_type(double) = 8, but
    - when -malign-double is not specified:  alignof_slot(double) = 4,
@@ -44,10 +48,4 @@
 # define alignof_type alignof_slot
 #endif
 
-/* alignof is an alias for alignof_slot semantics, since that's what most
-   callers need.
-   Note: The result cannot be used as a value for an 'enum' constant,
-   due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc.  */
-#define alignof alignof_slot
-
 #endif /* _ALIGNOF_H */