functional (_Maybe_wrap_member_pointer): Wrap up member pointers in _Mem_fn but let other function objects pass through...

2005-04-01  Douglas Gregor  <doug.gregor@gmail.com>

	* include/tr1/functional (_Maybe_wrap_member_pointer): Wrap up
	member pointers in _Mem_fn but let other function objects pass
	through unchanged.
	* include/tr1/functional_iterator (bind): Reduce number of bind()
	overloads to two to eliminate ambiguities. Use
	_Maybe_wrap_member_pointer to handle member pointers gracefully.

From-SVN: r97428

3 files changed, 53 insertions, 28 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 9873fb1..8c4f082 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,12 @@
+2005-04-01  Douglas Gregor  <doug.gregor@gmail.com>
+
+	* include/tr1/functional (_Maybe_wrap_member_pointer): Wrap up
+	member pointers in _Mem_fn but let other function objects pass
+	through unchanged.
+	* include/tr1/functional_iterator (bind): Reduce number of bind()
+	overloads to two to eliminate ambiguities. Use
+	_Maybe_wrap_member_pointer to handle member pointers gracefully.
+	
 2005-04-01  Mark Mitchell  <mark@codesourcery.com>
 
 	* testsuite/Makefile.am (noinst_PROGRAMS): Remove.
diff --git a/libstdc++-v3/include/tr1/functional b/libstdc++-v3/include/tr1/functional
index ab811d1..abe92e3 100644
--- a/libstdc++-v3/include/tr1/functional
+++ b/libstdc++-v3/include/tr1/functional
@@ -661,6 +661,34 @@ namespace tr1
 
   /**
    *  @if maint
+   *  Maps member pointers into instances of _Mem_fn but leaves all
+   *  other function objects untouched. Used by tr1::bind(). The
+   *  primary template handles the non--member-pointer case.
+   *  @endif
+   */
+  template<typename _Tp>
+    struct _Maybe_wrap_member_pointer
+    {
+      typedef _Tp type;
+      static const _Tp& __do_wrap(const _Tp& __x) { return __x; }
+    };
+
+  /**
+   *  @if maint
+   *  Maps member pointers into instances of _Mem_fn but leaves all
+   *  other function objects untouched. Used by tr1::bind(). This
+   *  partial specialization handles the member pointer case.
+   *  @endif
+   */
+  template<typename _Tp, typename _Class>
+    struct _Maybe_wrap_member_pointer<_Tp _Class::*>
+    {
+      typedef _Mem_fn<_Tp _Class::*> type;
+      static type __do_wrap(_Tp _Class::* __pm) { return type(__pm); }
+    };
+
+  /**
+   *  @if maint
    *  Type of the function object returned from bind().
    *  @endif
    */
diff --git a/libstdc++-v3/include/tr1/functional_iterate.h b/libstdc++-v3/include/tr1/functional_iterate.h
index 0a1ccee9..524f2d2 100644
--- a/libstdc++-v3/include/tr1/functional_iterate.h
+++ b/libstdc++-v3/include/tr1/functional_iterate.h
@@ -444,46 +444,34 @@ class _Bind_result<_Result, _Functor(_GLIBCXX_TEMPLATE_ARGS)>
 #undef _GLIBCXX_BIND_REPEAT_HEADER
 };
 
-// Handle member pointers
-template<typename _Tp, typename _Class _GLIBCXX_COMMA _GLIBCXX_TEMPLATE_PARAMS>
-inline _Bind<_Mem_fn<_Tp _Class::*>(_GLIBCXX_TEMPLATE_ARGS)>
-bind(_Tp _Class::* __pm _GLIBCXX_COMMA _GLIBCXX_PARAMS)
-{
-  typedef _Bind<_Mem_fn<_Tp _Class::*>(_GLIBCXX_TEMPLATE_ARGS)> __result_type;
-  return __result_type(_Mem_fn<_Tp _Class::*>(__pm)
-                       _GLIBCXX_COMMA _GLIBCXX_ARGS);
-}
-
-template<typename _Result, typename _Tp, typename _Class
-         _GLIBCXX_COMMA _GLIBCXX_TEMPLATE_PARAMS>
-inline _Bind_result<_Result, _Mem_fn<_Tp _Class::*>(_GLIBCXX_TEMPLATE_ARGS)>
-bind(_Tp _Class::* __pm _GLIBCXX_COMMA _GLIBCXX_PARAMS)
-{
-  typedef _Bind_result<_Result, _Mem_fn<_Tp _Class::*>(_GLIBCXX_TEMPLATE_ARGS)>
-    __result_type;
-  return __result_type(_Mem_fn<_Tp _Class::*>(__pm)
-                       _GLIBCXX_COMMA _GLIBCXX_ARGS);
-}
-
 // Handle arbitrary function objects
 template<typename _Functor _GLIBCXX_COMMA _GLIBCXX_TEMPLATE_PARAMS>
-inline _Bind<_Functor(_GLIBCXX_TEMPLATE_ARGS)>
+inline
+_Bind<typename _Maybe_wrap_member_pointer<_Functor>::type
+        (_GLIBCXX_TEMPLATE_ARGS)>
 bind(_Functor __f _GLIBCXX_COMMA _GLIBCXX_PARAMS)
 {
-  typedef _Bind<_Functor(_GLIBCXX_TEMPLATE_ARGS)> __result_type;
-  return __result_type(__f _GLIBCXX_COMMA _GLIBCXX_ARGS);
+  typedef _Maybe_wrap_member_pointer<_Functor> __maybe_type;
+  typedef typename __maybe_type::type __functor_type;
+  typedef _Bind<__functor_type(_GLIBCXX_TEMPLATE_ARGS)> __result_type;
+  return __result_type(__maybe_type::__do_wrap(__f)
+                       _GLIBCXX_COMMA _GLIBCXX_ARGS);
 }
 
 template<typename _Result, typename _Functor
          _GLIBCXX_COMMA _GLIBCXX_TEMPLATE_PARAMS>
 inline
-typename __enable_if<_Bind_result<_Result, _Functor(_GLIBCXX_TEMPLATE_ARGS)>,
-                     !is_member_pointer<_Functor>::value>::__type
+_Bind_result<_Result,
+             typename _Maybe_wrap_member_pointer<_Functor>::type
+               (_GLIBCXX_TEMPLATE_ARGS)>
 bind(_Functor __f _GLIBCXX_COMMA _GLIBCXX_PARAMS)
 {
-  typedef _Bind_result<_Result, _Functor(_GLIBCXX_TEMPLATE_ARGS)>
+  typedef _Maybe_wrap_member_pointer<_Functor> __maybe_type;
+  typedef typename __maybe_type::type __functor_type;
+  typedef _Bind_result<_Result, __functor_type(_GLIBCXX_TEMPLATE_ARGS)>
     __result_type;
-  return __result_type(__f _GLIBCXX_COMMA _GLIBCXX_ARGS);
+  return __result_type(__maybe_type::__do_wrap(__f)
+                       _GLIBCXX_COMMA _GLIBCXX_ARGS);
 }
 
 template<typename _Res, typename _Functor _GLIBCXX_COMMA