From d9072df2946363cd6b44b333e8b4315d70dd86d4 Mon Sep 17 00:00:00 2001
From: mat007 <mat007@860be788-9bd5-4423-9f1e-828f051e677b>
Date: Mon, 17 Jan 2011 23:16:45 +0000
Subject: [PATCH] Added lazy serialization of constraints

git-svn-id: https://svn.code.sf.net/p/turtle/code/trunk@197 860be788-9bd5-4423-9f1e-828f051e677b
---
 src/libraries/turtle/check.hpp  | 33 +++++++++++++++++++++------------
 src/libraries/turtle/lambda.hpp |  2 ++
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/src/libraries/turtle/check.hpp b/src/libraries/turtle/check.hpp
index 0314036..2083e3e 100644
--- a/src/libraries/turtle/check.hpp
+++ b/src/libraries/turtle/check.hpp
@@ -13,6 +13,7 @@
 #include "constraints.hpp"
 #include "operators.hpp"
 #include "format.hpp"
+#include "lambda.hpp"
 #include <boost/function.hpp>
 #include <boost/utility/enable_if.hpp>
 #include <boost/concept_check.hpp>
@@ -30,8 +31,8 @@ namespace detail
         BOOST_CONCEPT_USAGE( FunctorCompatible )
         {
             boost::require_boolean_expr(
-                // if an error is generated by the line below it means an argument
-                // passed to 'with' was of the wrong type.
+                // if an error is generated by the line below it means
+                // an argument passed to 'with' was of the wrong type.
                 functor_accepts( actual_argument_type )
             );
         }
@@ -48,8 +49,8 @@ namespace detail
         BOOST_CONCEPT_USAGE( EqualityComparable )
         {
             boost::require_boolean_expr(
-                // if an error is generated by the line below it means an argument
-                // passed to 'with' was of the wrong type.
+                // if an error is generated by the line below it means
+                // an argument passed to 'with' was of the wrong type.
                 actual_argument_type == expected_argument_type
             );
         }
@@ -68,7 +69,7 @@ namespace detail
             BOOST_DEDUCED_TYPENAME boost::enable_if<
                     BOOST_DEDUCED_TYPENAME detail::is_functor< Functor >
             >::type* = 0 )
-            : desc_( mock::format( f ) )
+            : desc_( bind( &serialize< Functor >, _1, f ) )
         {
             BOOST_CONCEPT_ASSERT(( FunctorCompatible< Functor, Actual > ));
             f_ = f;
@@ -80,18 +81,18 @@ namespace detail
             BOOST_DEDUCED_TYPENAME boost::disable_if<
                     BOOST_DEDUCED_TYPENAME detail::is_functor< Expected >
             >::type* = 0 )
-            : desc_( mock::format( expected ) )
+            : desc_( bind( &serialize< Expected >, _1, expected ) )
         {
             BOOST_CONCEPT_ASSERT(( EqualityComparable< Expected, Actual > ));
             f_ = mock::equal( expected ).f_;
             if( ! f_ )
                 std::invalid_argument( "invalid constraint" );
         }
-        template< typename Functor >
-        explicit check( const constraint< Functor >& ph )
-            : desc_( mock::format( ph.f_ ) )
+        template< typename Constraint >
+        explicit check( const constraint< Constraint >& ph )
+            : desc_( bind( &serialize< Constraint >, _1, ph.f_ ) )
         {
-            BOOST_CONCEPT_ASSERT(( FunctorCompatible< Functor, Actual > ));
+            BOOST_CONCEPT_ASSERT(( FunctorCompatible< Constraint, Actual > ));
             f_ = ph.f_;
             if( ! f_ )
                 std::invalid_argument( "invalid constraint" );
@@ -104,12 +105,20 @@ namespace detail
 
         friend std::ostream& operator<<( std::ostream& s, const check& c )
         {
-            return s << c.desc_;
+            c.desc_( s );
+            return s;
+        }
+
+    private:
+        template< typename T >
+        static void serialize( std::ostream& s, T t )
+        {
+            s << mock::format( t );
         }
 
     private:
         boost::function< bool( Actual ) > f_;
-        std::string desc_;
+        boost::function< void( std::ostream& ) > desc_;
     };
 }
 }
diff --git a/src/libraries/turtle/lambda.hpp b/src/libraries/turtle/lambda.hpp
index 641de0a..42fac3d 100644
--- a/src/libraries/turtle/lambda.hpp
+++ b/src/libraries/turtle/lambda.hpp
@@ -14,6 +14,7 @@
 #include <boost/bind.hpp>
 #else
 #include <boost/spirit/home/phoenix/bind.hpp>
+#include <boost/spirit/home/phoenix/core/argument.hpp>
 #endif
 #include <boost/function.hpp>
 
@@ -25,6 +26,7 @@ namespace detail
     using boost::bind;
 #else
     using boost::phoenix::bind;
+    using boost::phoenix::arg_names::_1;
 #endif
 
     template< typename Result, typename Signature >