diff --git a/build/vc80/turtle.vcproj b/build/vc80/turtle.vcproj
index b44e6e4..25b6967 100644
--- a/build/vc80/turtle.vcproj
+++ b/build/vc80/turtle.vcproj
@@ -169,7 +169,7 @@
 				>
 			</File>
 			<File
-				RelativePath="..\..\src\libraries\turtle\constraint.hpp"
+				RelativePath="..\..\src\libraries\turtle\constraints.hpp"
 				>
 			</File>
 			<File
@@ -212,6 +212,10 @@
 				RelativePath="..\..\src\libraries\turtle\object.hpp"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\libraries\turtle\operators.hpp"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\libraries\turtle\placeholder.hpp"
 				>
diff --git a/build/vc80/turtle_test.vcproj b/build/vc80/turtle_test.vcproj
index 27fe1ff..e547f4a 100644
--- a/build/vc80/turtle_test.vcproj
+++ b/build/vc80/turtle_test.vcproj
@@ -191,7 +191,7 @@
 			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm;asmx;h;hpp;hxx;hm;inl;inc;xsd"
 			>
 			<File
-				RelativePath="..\..\src\tests\turtle_test\constraint_test.cpp"
+				RelativePath="..\..\src\tests\turtle_test\constraints_test.cpp"
 				>
 			</File>
 			<File
diff --git a/src/libraries/turtle/check.hpp b/src/libraries/turtle/check.hpp
index 01f0e15..13b1343 100644
--- a/src/libraries/turtle/check.hpp
+++ b/src/libraries/turtle/check.hpp
@@ -10,8 +10,8 @@
 #define MOCK_CHECK_HPP_INCLUDED
 
 #include "placeholder.hpp"
-#include "constraint.hpp"
 #include "is_functor.hpp"
+#include "constraints.hpp"
 #include "format.hpp"
 #include <boost/function.hpp>
 #include <boost/utility/enable_if.hpp>
diff --git a/src/libraries/turtle/constraint.hpp b/src/libraries/turtle/constraints.hpp
similarity index 68%
rename from src/libraries/turtle/constraint.hpp
rename to src/libraries/turtle/constraints.hpp
index 24b2581..0d322af 100644
--- a/src/libraries/turtle/constraint.hpp
+++ b/src/libraries/turtle/constraints.hpp
@@ -6,38 +6,14 @@
 //  http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef MOCK_CONSTRAINT_HPP_INCLUDED
-#define MOCK_CONSTRAINT_HPP_INCLUDED
+#ifndef MOCK_CONSTRAINTS_HPP_INCLUDED
+#define MOCK_CONSTRAINTS_HPP_INCLUDED
 
-#include "placeholder.hpp"
 #include "functional.hpp"
-#include "format.hpp"
-#include <sstream>
+#include "operators.hpp"
 
 namespace mock
 {
-    template< typename Functor, typename Description >
-    const detail::placeholder< Functor > constraint( const Functor& f,
-                                                     const Description& desc )
-    {
-        std::stringstream s;
-        s << std::boolalpha << desc;
-        return detail::placeholder< Functor >( f, s.str() );
-    }
-    template< typename Functor >
-    const detail::placeholder< Functor > constraint( const Functor& f )
-    {
-        return detail::placeholder< Functor >( f, "?" );
-    }
-    template< typename Functor, typename T >
-    const detail::placeholder< Functor > constraint( const Functor& f,
-                                                     const std::string& name,
-                                                     const T& t )
-    {
-        return detail::placeholder< Functor >( f,
-            name + "( " + format( t ) + " )" );
-    }
-
 namespace detail
 {
     template<>
@@ -135,4 +111,4 @@ namespace detail
     }
 }
 
-#endif // #ifndef MOCK_CONSTRAINT_HPP_INCLUDED
+#endif // #ifndef MOCK_CONSTRAINTS_HPP_INCLUDED
diff --git a/src/libraries/turtle/expectation.hpp b/src/libraries/turtle/expectation.hpp
index df2d24b..fff3818 100644
--- a/src/libraries/turtle/expectation.hpp
+++ b/src/libraries/turtle/expectation.hpp
@@ -14,7 +14,7 @@
 #include "action.hpp"
 #include "sequence.hpp"
 #include "check.hpp"
-#include "constraint.hpp"
+#include "constraints.hpp"
 #include <boost/shared_ptr.hpp>
 #include <boost/preprocessor/repetition/repeat_from_to.hpp>
 #include <boost/preprocessor/repetition/enum_params.hpp>
diff --git a/src/libraries/turtle/operators.hpp b/src/libraries/turtle/operators.hpp
new file mode 100644
index 0000000..8a1f2e9
--- /dev/null
+++ b/src/libraries/turtle/operators.hpp
@@ -0,0 +1,100 @@
+//
+//  Copyright Mathieu Champlon 2010
+//
+//  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)
+//
+
+#ifndef MOCK_OPERATORS_HPP_INCLUDED
+#define MOCK_OPERATORS_HPP_INCLUDED
+
+#include "placeholder.hpp"
+
+namespace mock
+{
+namespace detail
+{
+    template< typename Functor1, typename Functor2 >
+    class and_
+    {
+    public:
+        and_( const Functor1& f1, const Functor2& f2 )
+            : f1_( f1 )
+            , f2_( f2 )
+        {}
+        template< typename Actual >
+        bool operator()( const Actual& actual ) const
+        {
+            return f1_( actual ) && f2_( actual );
+        }
+    private:
+        Functor1 f1_;
+        Functor2 f2_;
+    };
+
+    template< typename Functor1, typename Functor2 >
+    class or_
+    {
+    public:
+        or_( const Functor1& f1, const Functor2& f2 )
+            : f1_( f1 )
+            , f2_( f2 )
+        {}
+        template< typename Actual >
+        bool operator()( const Actual& actual ) const
+        {
+            return f1_( actual ) || f2_( actual );
+        }
+    private:
+        Functor1 f1_;
+        Functor2 f2_;
+    };
+
+    template< typename Functor >
+    class not_
+    {
+    public:
+        explicit not_( const Functor& f )
+            : f_( f )
+        {}
+        template< typename Actual >
+        bool operator()( const Actual& actual ) const
+        {
+            return ! f_( actual );
+        }
+    private:
+        Functor f_;
+    };
+
+    template< typename Functor1, typename Functor2 >
+    const placeholder< or_< Functor1, Functor2 > >
+        operator||( const placeholder< Functor1 >& lhs,
+                    const placeholder< Functor2 >& rhs )
+    {
+        return constraint(
+            or_< Functor1, Functor2 >( lhs.f_, rhs.f_ ),
+            "(" + lhs.desc_ + " || " + rhs.desc_ + ")" );
+    }
+
+    template< typename Functor1, typename Functor2 >
+    const placeholder< and_< Functor1, Functor2 > >
+        operator&&( const placeholder< Functor1 >& lhs,
+                    const placeholder< Functor2 >& rhs )
+    {
+        return constraint(
+            and_< Functor1, Functor2 >( lhs.f_, rhs.f_ ),
+            "(" + lhs.desc_ + " && " + rhs.desc_ + ")" );
+    }
+
+    template< typename Functor >
+    const placeholder< not_< Functor > >
+        operator!( const placeholder< Functor >& ph )
+    {
+        return constraint(
+            not_< Functor >( ph.f_ ), "! " + ph.desc_ );
+    }
+}
+}
+
+#endif // #ifndef MOCK_OPERATORS_HPP_INCLUDED
diff --git a/src/libraries/turtle/placeholder.hpp b/src/libraries/turtle/placeholder.hpp
index 0470d04..13c41e1 100644
--- a/src/libraries/turtle/placeholder.hpp
+++ b/src/libraries/turtle/placeholder.hpp
@@ -9,7 +9,7 @@
 #ifndef MOCK_PLACEHOLDER_HPP_INCLUDED
 #define MOCK_PLACEHOLDER_HPP_INCLUDED
 
-#include <string>
+#include "format.hpp"
 
 namespace mock
 {
@@ -25,87 +25,29 @@ namespace detail
         Functor f_;
         std::string desc_;
     };
-
-    template< typename Functor1, typename Functor2 >
-    class and_
-    {
-    public:
-        and_( const Functor1& f1, const Functor2& f2 )
-            : f1_( f1 )
-            , f2_( f2 )
-        {}
-        template< typename Actual >
-        bool operator()( const Actual& actual ) const
-        {
-            return f1_( actual ) && f2_( actual );
-        }
-    private:
-        Functor1 f1_;
-        Functor2 f2_;
-    };
-
-    template< typename Functor1, typename Functor2 >
-    class or_
-    {
-    public:
-        or_( const Functor1& f1, const Functor2& f2 )
-            : f1_( f1 )
-            , f2_( f2 )
-        {}
-        template< typename Actual >
-        bool operator()( const Actual& actual ) const
-        {
-            return f1_( actual ) || f2_( actual );
-        }
-    private:
-        Functor1 f1_;
-        Functor2 f2_;
-    };
-
-    template< typename Functor >
-    class not_
-    {
-    public:
-        explicit not_( const Functor& f )
-            : f_( f )
-        {}
-        template< typename Actual >
-        bool operator()( const Actual& actual ) const
-        {
-            return ! f_( actual );
-        }
-    private:
-        Functor f_;
-    };
-
-    template< typename F1, typename F2 >
-    const placeholder< or_< F1, F2 > >
-        operator||( const placeholder< F1 >& lhs,
-                    const placeholder< F2 >& rhs )
-    {
-        return placeholder< or_< F1, F2 > >(
-            or_< F1, F2 >( lhs.f_, rhs.f_ ),
-            "(" + lhs.desc_ + " || " + rhs.desc_ + ")" );
-    }
-
-    template< typename F1, typename F2 >
-    const placeholder< and_< F1, F2 > >
-        operator&&( const placeholder< F1 >& lhs,
-                    const placeholder< F2 >& rhs )
-    {
-        return placeholder< and_< F1, F2 > >(
-            and_< F1, F2 >( lhs.f_, rhs.f_ ),
-            "(" + lhs.desc_ + " && " + rhs.desc_ + ")" );
-    }
-
-    template< typename F >
-    const placeholder< not_< F > >
-        operator!( const placeholder< F >& ph )
-    {
-        return placeholder< not_< F > >(
-            not_< F >( ph.f_ ), "! " + ph.desc_ );
-    }
 }
+
+    template< typename Functor, typename Description >
+    const detail::placeholder< Functor > constraint( const Functor& f,
+                                                     const Description& desc )
+    {
+        std::stringstream s;
+        s << std::boolalpha << desc;
+        return detail::placeholder< Functor >( f, s.str() );
+    }
+    template< typename Functor >
+    const detail::placeholder< Functor > constraint( const Functor& f )
+    {
+        return detail::placeholder< Functor >( f, "?" );
+    }
+    template< typename Functor, typename T >
+    const detail::placeholder< Functor > constraint( const Functor& f,
+                                                     const std::string& name,
+                                                     const T& t )
+    {
+        return detail::placeholder< Functor >( f,
+            name + "( " + format( t ) + " )" );
+    }
 }
 
 #endif // #ifndef MOCK_PLACEHOLDER_HPP_INCLUDED
diff --git a/src/tests/turtle_test/constraint_test.cpp b/src/tests/turtle_test/constraints_test.cpp
similarity index 94%
rename from src/tests/turtle_test/constraint_test.cpp
rename to src/tests/turtle_test/constraints_test.cpp
index df577a4..2ee756d 100644
--- a/src/tests/turtle_test/constraint_test.cpp
+++ b/src/tests/turtle_test/constraints_test.cpp
@@ -6,7 +6,7 @@
 //  http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#include <turtle/constraint.hpp>
+#include <turtle/constraints.hpp>
 
 #include <boost/test/auto_unit_test.hpp>
 #define BOOST_LIB_NAME boost_unit_test_framework