is_placeholder, is_bind_expression added.

[SVN r34468]

include/boost/bind.hpp

@@ -25,6 +25,7 @@
 #include <boost/ref.hpp>
 #include <boost/mem_fn.hpp>
 #include <boost/type.hpp>
+#include <boost/is_placeholder.hpp>
 #include <boost/bind/arg.hpp>
 #include <boost/detail/workaround.hpp>
 #include <boost/visit_each.hpp>
@@ -933,11 +934,32 @@ namespace _bi
 
 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) || (__SUNPRO_CC >= 0x530)
 
+#if 0
+
 template<class T> struct add_value
 {
     typedef _bi::value<T> type;
 };
 
+#else
+
+template< class T, int I > struct add_value_2
+{
+    typedef boost::arg<I> type;
+};
+
+template< class T > struct add_value_2< T, 0 >
+{
+    typedef _bi::value< T > type;
+};
+
+template<class T> struct add_value
+{
+    typedef typename add_value_2< T, boost::is_placeholder< T >::value >::type type;
+};
+
+#endif
+
 template<class T> struct add_value< value<T> >
 {
     typedef _bi::value<T> type;
@@ -1194,6 +1216,22 @@ template<class V, class R, class F, class L> void visit_each( V & v, _bi::bind_t
 
 #endif
 
+// is_bind_expression
+
+template< class T > struct is_bind_expression
+{
+    enum _vt { value = 0 };
+};
+
+#if !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )
+
+template< class R, class F, class L > struct is_bind_expression< _bi::bind_t< R, F, L > >
+{
+    enum _vt { value = 1 };
+};
+
+#endif
+
 // bind
 
 #ifndef BOOST_BIND

include/boost/bind/arg.hpp

@@ -19,18 +19,44 @@
 //  See http://www.boost.org/libs/bind/bind.html for documentation.
 //
 
+#include <boost/config.hpp>
+#include <boost/is_placeholder.hpp>
+
 namespace boost
 {
 
-template<int I> class arg
+template< int I > struct arg
 {
+    arg()
+    {
+    }
+
+    template< class T > arg( T const & /* t */ )
+    {
+        // static assert I == is_placeholder<T>::value
+        typedef char T_must_be_placeholder[ I == is_placeholder<T>::value? 1: -1 ];
+    }
 };
 
-template<int I> bool operator==(arg<I> const &, arg<I> const &)
+template< int I > bool operator==( arg<I> const &, arg<I> const & )
 {
     return true;
 }
 
+#if !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )
+
+template< int I > struct is_placeholder< arg<I> >
+{
+    enum _vt { value = I };
+};
+
+template< int I > struct is_placeholder< arg<I> (*) () >
+{
+    enum _vt { value = I };
+};
+
+#endif
+
 } // namespace boost
 
 #endif // #ifndef BOOST_BIND_ARG_HPP_INCLUDED

include/boost/is_placeholder.hpp

@@ -0,0 +1,31 @@
+#ifndef BOOST_IS_PLACEHOLDER_HPP_INCLUDED
+#define BOOST_IS_PLACEHOLDER_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined( _MSC_VER ) && ( _MSC_VER >= 1020 )
+# pragma once
+#endif
+
+
+//  is_placeholder.hpp - TR1 is_placeholder metafunction
+//
+//  Copyright (c) 2006 Peter Dimov
+//
+//  Distributed under the Boost Software License, Version 1.0.
+//
+//  See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt
+
+
+namespace boost
+{
+
+template< class T > struct is_placeholder
+{
+    enum _vt { value = 0 };
+};
+
+} // namespace boost
+
+#endif // #ifndef BOOST_IS_PLACEHOLDER_HPP_INCLUDED