Unordered/hash: Avoid a gcc warning. Refs #6771

[SVN r77832]
2012-04-08 15:29:15 +00:00
parent 01aba11b87
commit 3910f072cd
5 changed files with 29 additions and 3 deletions
@@ -86,10 +86,24 @@ namespace boost
 {
    namespace hash_detail
    {
+        template <class T>
+        inline bool is_zero(T v)
+        {
+#if !defined(__GNUC__)
+            return v == 0;
+#else
+            // GCC's '-Wfloat-equal' will complain about comparing
+            // v to 0, but because it disables warnings for system
+            // headers it won't complain if you use std::equal_to to
+            // compare with 0. Resulting in this silliness:
+            return std::equal_to<T>()(v, 0);
+#endif
+        }
+
        template <class T>
        inline std::size_t float_hash_value(T v)
        {
-            return v == 0 ? 0 : float_hash_impl(v);
+            return boost::hash_detail::is_zero(v) ? 0 : float_hash_impl(v);
        }
    }
 }