is_sequence initial checkin

[SVN r16398]

include/boost/mpl/aux_/begin_end_impl.hpp

@@ -18,6 +18,7 @@
 #define BOOST_MPL_AUX_BEGIN_END_IMPL_HPP_INCLUDED
 
 #include "boost/mpl/begin_end_fwd.hpp"
+#include "boost/mpl/sequence_tag_fwd.hpp"
 #include "boost/mpl/aux_/traits_lambda_spec.hpp"
 #include "boost/mpl/aux_/config/eti.hpp"
 
@@ -25,8 +26,8 @@ namespace boost {
 namespace mpl {
 
 // default implementation; conrete sequences might override it by 
-// specializing either the |begin_traits/end_traits| or the primary 
+// specializing either the 'begin_traits/end_traits' or the primary 
-// |begin/end| templates
+// 'begin/end' templates
 
 template< typename Tag >
 struct begin_traits
@@ -46,24 +47,37 @@ struct end_traits
     };
 };
 
-#if defined(BOOST_MPL_MSVC_ETI_BUG)
+// specialize 'begin_trait/end_trait' for two pre-defined tags
-template<> struct begin_traits<int>
-{
-    template< typename Sequence > struct algorithm
-    {
-        typedef int type;
-    };
-};
 
-template<> struct end_traits<int>
+#   define AUX_AGLORITM_TRAIT_SPEC(name, tag, result) \
-{
+template<> \
-    template< typename Sequence > struct algorithm
+struct name##_traits<tag> \
-    {
+{ \
-        typedef int type;
+    template< typename Sequence > struct algorithm  \
-    };
+    { \
-};
+        typedef result type; \
+    }; \
+}; \
+/**/
+
+// a sequence with nested 'begin/end' typedefs; just query them
+AUX_AGLORITM_TRAIT_SPEC(begin, nested_begin_end_tag, typename Sequence::begin)
+AUX_AGLORITM_TRAIT_SPEC(end, nested_begin_end_tag, typename Sequence::end)
+
+// if a type 'T' does not contain 'begin/end' or 'tag' members 
+// and doesn't specialize either 'begin/end' or 'begin_traits/end_traits' 
+// templates, then we end up here
+AUX_AGLORITM_TRAIT_SPEC(begin, non_sequence_tag, non_sequence_tag)
+AUX_AGLORITM_TRAIT_SPEC(end, non_sequence_tag, non_sequence_tag)
+
+#if defined(BOOST_MPL_MSVC_ETI_BUG)
+AUX_AGLORITM_TRAIT_SPEC(begin, int, non_sequence_tag)
+AUX_AGLORITM_TRAIT_SPEC(end, int, non_sequence_tag)
 #endif
 
+#   undef AUX_AGLORITM_TRAIT_SPEC
+
+
 BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1,begin_traits)
 BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1,end_traits)
 

include/boost/mpl/aux_/has_begin.hpp

@@ -0,0 +1,26 @@
+//-----------------------------------------------------------------------------
+// boost mpl/aux_/has_begin.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2002
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_AUX_HAS_BEGIN_HPP_INCLUDED
+#define BOOST_MPL_AUX_HAS_BEGIN_HPP_INCLUDED
+
+#include "boost/mpl/aux_/has_xxx.hpp"
+
+namespace boost { namespace mpl { namespace aux {
+BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_begin, begin, true)
+}}}
+
+#endif // BOOST_MPL_AUX_HAS_BEGIN_HPP_INCLUDED

include/boost/mpl/aux_/has_rebind.hpp

@@ -24,7 +24,7 @@
 
 namespace boost { namespace mpl { namespace aux {
 
-BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_rebind_impl, rebind)
+BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_rebind_impl, rebind, false)
 
 template< typename T >
 struct has_rebind

include/boost/mpl/aux_/has_tag.hpp

@@ -0,0 +1,26 @@
+//-----------------------------------------------------------------------------
+// boost mpl/aux_/has_tag.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2002
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_AUX_HAS_TAG_HPP_INCLUDED
+#define BOOST_MPL_AUX_HAS_TAG_HPP_INCLUDED
+
+#include "boost/mpl/aux_/has_xxx.hpp"
+
+namespace boost { namespace mpl { namespace aux {
+BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_tag, tag, true)
+}}}
+
+#endif // BOOST_MPL_AUX_HAS_TAG_HPP_INCLUDED

include/boost/mpl/aux_/has_xxx.hpp

@@ -32,7 +32,7 @@
 // the implementation below is based on a USENET newsgroup's posting by  
 // Rani Sharoni (comp.lang.c++.moderated, 2002-03-17 07:45:09 PST)
 
-#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name) \
+#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \
 template< typename T > \
 boost::mpl::aux::yes_tag \
 trait##_helper( \
@@ -66,7 +66,7 @@ namespace boost { namespace mpl { namespace aux {
 struct has_xxx_tag;
 }}}
 
-#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name) \
+#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \
 template< typename T, typename name = ::boost::mpl::aux::has_xxx_tag > \
 struct trait : T \
 { \
@@ -105,13 +105,13 @@ template<> struct trait<T,boost::mpl::aux::has_xxx_tag> \
 /**/
 
 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
-#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name) \
+#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \
-    BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name) \
+    BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \
     BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, wchar_t) \
     /**/
 #else
-#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name) \
+#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \
-    BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name) \
+    BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \
     /**/
 #endif
 
@@ -119,18 +119,18 @@ template<> struct trait<T,boost::mpl::aux::has_xxx_tag> \
 
 #else 
 
-#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name) \
+#   define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_value) \
 template< typename T > \
 struct trait \
 { \
-     BOOST_STATIC_CONSTANT(bool, value = false); \
+     BOOST_STATIC_CONSTANT(bool, value = default_value); \
 }; \
 /**/
 
 #endif // BOOST_MPL_BROKEN_OVERLOAD_RESOLUTION
 
 #define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \
-BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_##name, name) \
+BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_##name, name, false) \
 /**/
 
 #endif // BOOST_MPL_AUX_HAS_XXX_HPP_INCLUDED

include/boost/mpl/aux_/sequence_tag.hpp

@@ -20,10 +20,14 @@
 //#include "boost/mpl/aux_/config/internal.hpp"
 #include "boost/config.hpp"
 
-#if defined(BOOST_MPL_INTERNAL_USE_SEQUENCE_TAG) || \
+#if !defined(BOOST_MPL_INTERNAL_USE_SEQUENCE_TAG)
-    defined(BOOST_MSVC) && BOOST_MSVC < 1300
+#   define BOOST_MPL_INTERNAL_USE_SEQUENCE_TAG
-#   include "boost/mpl/sequence_tag.hpp"
+#endif
 
+#if defined(BOOST_MPL_INTERNAL_USE_SEQUENCE_TAG) \
+ || defined(BOOST_MSVC) && BOOST_MSVC < 1300
+
+#   include "boost/mpl/sequence_tag.hpp"
 #   define BOOST_MPL_AUX_SEQUENCE_TAG(seq) sequence_tag<seq>::type
 
 #else

include/boost/mpl/is_sequence.hpp

@@ -0,0 +1,51 @@
+//-----------------------------------------------------------------------------
+// boost mpl/is_sequence.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2002
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_IS_SEQUENCE_HPP_INCLUDED
+#define BOOST_MPL_IS_SEQUENCE_HPP_INCLUDED
+
+#include "boost/mpl/logical/not.hpp"
+#include "boost/mpl/begin_end.hpp"
+#include "boost/mpl/sequence_tag_fwd.hpp"
+#include "boost/mpl/aux_/void_spec.hpp"
+#include "boost/mpl/aux_/lambda_support.hpp"
+#include "boost/mpl/aux_/config/eti.hpp"
+
+#include "boost/type_traits/is_same.hpp"
+
+namespace boost { namespace mpl {
+
+template<
+      typename BOOST_MPL_AUX_VOID_SPEC_PARAM(T)
+    >
+struct is_sequence
+    : logical_not< is_same< typename begin<T>::type, non_sequence_tag > >
+{
+    BOOST_MPL_AUX_LAMBDA_SUPPORT(1,is_sequence,(T))
+};
+
+#if defined(BOOST_MPL_MSVC_ETI_BUG)
+template<> struct is_sequence<int>
+    : bool_c<false>
+{
+};
+#endif
+
+BOOST_MPL_AUX_VOID_SPEC(1, is_sequence)
+
+}} // namespace boost::mpl
+
+#endif // BOOST_MPL_IS_SEQUENCE_HPP_INCLUDED

include/boost/mpl/sequence_tag.hpp

@@ -17,30 +17,86 @@
 #ifndef BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED
 #define BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED
 
+#include "boost/mpl/sequence_tag_fwd.hpp"
+#include "boost/mpl/aux_/has_tag.hpp"
+#include "boost/mpl/aux_/has_begin.hpp"
 #include "boost/mpl/aux_/void_spec.hpp"
 #include "boost/mpl/aux_/config/eti.hpp"
 
-namespace boost {
+#include "boost/type_traits/is_class.hpp"
-namespace mpl {
+
+namespace boost { namespace mpl {
+
+namespace aux {
+
+template< bool has_tag_, bool has_begin_ >
+struct class_sequence_tag_impl
+{
+    // agurt 24/nov/02: MSVC 6.5 gets confused in 'sequence_tag_impl<true>' 
+    // specialization below, if we name it 'result_' here
+    template< typename Sequence > struct result2_;
+};
+
+#   define AUX_CLASS_SEQUENCE_TAG_SPEC(has_tag, has_begin, result_type) \
+template<> struct class_sequence_tag_impl<has_tag,has_begin> \
+{ \
+    template< typename Sequence > struct result2_ \
+    { \
+        typedef result_type type; \
+    }; \
+}; \
+/**/
+
+AUX_CLASS_SEQUENCE_TAG_SPEC(true, true, typename Sequence::tag)
+AUX_CLASS_SEQUENCE_TAG_SPEC(true, false, typename Sequence::tag)
+AUX_CLASS_SEQUENCE_TAG_SPEC(false, true, nested_begin_end_tag)
+AUX_CLASS_SEQUENCE_TAG_SPEC(false, false, non_sequence_tag)
+
+#   undef AUX_CLASS_SEQUENCE_TAG_SPEC
+
+
+template< bool is_class_ >
+struct sequence_tag_impl
+{
+    template< typename Sequence > struct result_
+    {
+        typedef non_sequence_tag type;
+    };
+};
+
+template<>
+struct sequence_tag_impl<true>
+{
+    template< typename Sequence > struct result_
+        : class_sequence_tag_impl<
+              ::boost::mpl::aux::has_tag<Sequence>::value
+            , ::boost::mpl::aux::has_begin<Sequence>::value
+            >::template result2_<Sequence>
+    {
+    };
+};
+
+} // namespace aux
 
 template<
       typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Sequence)
     >
 struct sequence_tag
+    : aux::sequence_tag_impl<
+          ::boost::is_class<Sequence>::value
+        >::template result_<Sequence>
 {
-    typedef typename Sequence::tag type;
 };
 
 #if defined(BOOST_MPL_MSVC_ETI_BUG)
 template<> struct sequence_tag<int>
 {
-    typedef int type;
+    typedef non_sequence_tag type;
 };
 #endif
 
 BOOST_MPL_AUX_VOID_SPEC(1, sequence_tag)
 
-} // namespace mpl
+}} // namespace boost::mpl
-} // namespace boost
 
 #endif // BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED

include/boost/mpl/sequence_tag_fwd.hpp

@@ -0,0 +1,29 @@
+//-----------------------------------------------------------------------------
+// boost mpl/sequence_tag_fwd.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2000-02
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_SEQUENCE_TAG_FWD_HPP_INCLUDED
+#define BOOST_MPL_SEQUENCE_TAG_FWD_HPP_INCLUDED
+
+namespace boost { namespace mpl {
+
+struct nested_begin_end_tag;
+struct non_sequence_tag;
+
+template< typename Sequence > struct sequence_tag;
+
+}} // namespace boost::mpl
+
+#endif // BOOST_MPL_SEQUENCE_TAG_FWD_HPP_INCLUDED