contrib-json_spirit:  adding library to reduce external dependencies

moreover, the current macports version is not usable due to a missing
header

Change-Id: I7cd80ecf17b1ca50e5c71badba56d0bf3d390f4f
diff --git a/contrib/json_spirit/json_spirit_utils.h b/contrib/json_spirit/json_spirit_utils.h
new file mode 100644
index 0000000..c492309
--- /dev/null
+++ b/contrib/json_spirit/json_spirit_utils.h
@@ -0,0 +1,63 @@
+#ifndef JSON_SPIRIT_UTILS

+#define JSON_SPIRIT_UTILS

+

+//          Copyright John W. Wilkinson 2007 - 2011

+// Distributed under the MIT License, see accompanying file LICENSE.txt

+

+// json spirit version 4.05

+

+#if defined(_MSC_VER) && (_MSC_VER >= 1020)

+# pragma once

+#endif

+

+#include "json_spirit_value.h"

+#include <map>

+

+namespace json_spirit

+{ 

+    template< class Obj_t, class Map_t >

+    void obj_to_map( const Obj_t& obj, Map_t& mp_obj )

+    {

+        mp_obj.clear();

+

+        for( typename Obj_t::const_iterator i = obj.begin(); i != obj.end(); ++i )

+        {

+            mp_obj[ i->name_ ] = i->value_;

+        }

+    }

+

+    template< class Obj_t, class Map_t >

+    void map_to_obj( const Map_t& mp_obj, Obj_t& obj )

+    {

+        obj.clear();

+

+        for( typename Map_t::const_iterator i = mp_obj.begin(); i != mp_obj.end(); ++i )

+        {

+            obj.push_back( typename Obj_t::value_type( i->first, i->second ) );

+        }

+    }

+

+#ifdef JSON_SPIRIT_VALUE_ENABLED

+    typedef std::map< std::string, Value > Mapped_obj;

+#endif

+

+#if defined( JSON_SPIRIT_WVALUE_ENABLED ) && !defined( BOOST_NO_STD_WSTRING )

+    typedef std::map< std::wstring, wValue > wMapped_obj;

+#endif

+

+    template< class Object_type, class String_type >

+    const typename Object_type::value_type::Value_type& find_value( const Object_type& obj, const String_type& name )

+    {

+        for( typename Object_type::const_iterator i = obj.begin(); i != obj.end(); ++i )

+        {

+            if( i->name_ == name )

+            {

+                return i->value_;

+            }

+        }

+

+        return Object_type::value_type::Value_type::null;

+    }

+}

+

+#endif