From d1a2e748f887fb231f698f4b3a35d6aff0cf259e Mon Sep 17 00:00:00 2001
From: Eric Friedman <ebf@users.sourceforge.net>
Date: Fri, 7 Nov 2003 04:30:08 +0000
Subject: [PATCH] Added public interface to iter_fold_if.

[SVN r20716]
---
 include/boost/mpl/index_if.hpp     | 36 +++++--------
 include/boost/mpl/iter_fold_if.hpp | 83 ++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+), 24 deletions(-)
 create mode 100644 include/boost/mpl/iter_fold_if.hpp

diff --git a/include/boost/mpl/index_if.hpp b/include/boost/mpl/index_if.hpp
index 9b4ad5d..2740788 100644
--- a/include/boost/mpl/index_if.hpp
+++ b/include/boost/mpl/index_if.hpp
@@ -19,14 +19,13 @@
 
 #include "boost/mpl/aux_/config/workaround.hpp"
 #include "boost/mpl/aux_/find_if_pred.hpp"
-#include "boost/mpl/aux_/iter_fold_if_impl.hpp"
-#include "boost/mpl/always.hpp"
 #include "boost/mpl/begin_end.hpp"
-#include "boost/mpl/bool.hpp"
 #include "boost/mpl/if.hpp"
 #include "boost/mpl/int.hpp"
+#include "boost/mpl/iter_fold_if.hpp"
 #include "boost/mpl/lambda.hpp"
 #include "boost/mpl/next.hpp"
+#include "boost/mpl/protect.hpp"
 #include "boost/mpl/void.hpp"
 #include "boost/mpl/aux_/void_spec.hpp"
 #include "boost/mpl/aux_/lambda_support.hpp"
@@ -56,35 +55,24 @@ template<
     >
 struct index_if
 {
- private:
+private:
+
     typedef typename begin<Sequence>::type first_;
     typedef typename end<Sequence>::type last_;
     typedef typename lambda<Predicate>::type pred_;
 
-// cwpro8 doesn't like 'cut-off' type here (use typedef instead)
-#if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
-    struct result_ :
-#else
-    typedef
-#endif
-        aux::iter_fold_if_impl<
+    typedef typename iter_fold_if<
           first_
         , int_<0>
-        , aux::index_if_op
-        , aux::find_if_pred<pred_,last_>
-        , void
-        , always<false_>
-        >
-#if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
-    { };
-#else
-    result_;
-#endif
+        , protect< aux::index_if_op >
+        , protect< aux::find_if_pred<pred_,last_> >
+        >::type result_;
 
-    typedef typename result_::state result_index_;
-    typedef typename result_::iterator result_iterator_;
+    typedef typename result_::first result_index_;
+    typedef typename result_::second result_iterator_;
+
+public:
 
- public:
     typedef typename if_<
           is_same< result_iterator_,last_ >
         , void_
diff --git a/include/boost/mpl/iter_fold_if.hpp b/include/boost/mpl/iter_fold_if.hpp
new file mode 100644
index 0000000..3c2a332
--- /dev/null
+++ b/include/boost/mpl/iter_fold_if.hpp
@@ -0,0 +1,83 @@
+//-----------------------------------------------------------------------------
+// boost mpl/iter_fold_if.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2003
+// Eric Friedman
+//
+// 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_ITER_FOLD_IF_HPP_INCLUDED
+#define BOOST_MPL_ITER_FOLD_IF_HPP_INCLUDED
+
+#include "boost/mpl/aux_/iter_fold_if_impl.hpp"
+#include "boost/mpl/always.hpp"
+#include "boost/mpl/bool.hpp"
+#include "boost/mpl/lambda.hpp"
+#include "boost/mpl/pair.hpp"
+#include "boost/mpl/void.hpp"
+#include "boost/mpl/aux_/void_spec.hpp"
+#include "boost/mpl/aux_/lambda_support.hpp"
+
+namespace boost {
+namespace mpl {
+
+template<
+      typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Iterator)
+    , typename BOOST_MPL_AUX_VOID_SPEC_PARAM(State)
+    , typename BOOST_MPL_AUX_VOID_SPEC_PARAM(ForwardOp)
+    , typename BOOST_MPL_AUX_VOID_SPEC_PARAM(ForwardPredicate)
+    , typename BackwardOp = void_
+    , typename BackwardPredicate = always<false_>
+    >
+struct iter_fold_if
+{
+private:
+
+// cwpro8 doesn't like 'cut-off' type here (use typedef instead)
+#if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+    struct result_ :
+#else
+    typedef
+#endif
+        aux::iter_fold_if_impl<
+          Iterator
+        , State
+        , typename lambda<ForwardOp>::type
+        , typename lambda<ForwardPredicate>::type
+        , typename lambda<BackwardOp>::type
+        , typename lambda<BackwardPredicate>::type
+        >
+#if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+    { };
+#else
+    result_;
+#endif
+
+public:
+
+    typedef pair<
+          typename result_::state
+        , typename result_::iterator
+        > type;
+
+    BOOST_MPL_AUX_LAMBDA_SUPPORT(
+          6
+        , iter_fold_if
+        , (Iterator,State,ForwardOp,ForwardPredicate,BackwardOp,BackwardPredicate)
+        )
+};
+
+BOOST_MPL_AUX_VOID_SPEC(4, iter_fold_if)
+
+} // namespace mpl
+} // namespace boost
+
+#endif // BOOST_MPL_ITER_FOLD_IF_HPP_INCLUDED