Split out internal error macros from the common path

include/internal/catch_enforce.h

@@ -0,0 +1,24 @@
+/*
+ *  Created by Martin on 01/08/2017.
+ *
+ *  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 TWOBLUECUBES_CATCH_ENFORCE_H_INCLUDED
+#define TWOBLUECUBES_CATCH_ENFORCE_H_INCLUDED
+
+#include "catch_common.h"
+
+#include <sstream>
+#include <exception>
+
+#define CATCH_PREPARE_EXCEPTION( type, msg ) \
+    type( static_cast<std::ostringstream&&>( std::ostringstream() << msg ).str() )
+#define CATCH_INTERNAL_ERROR( msg ) \
+    throw CATCH_PREPARE_EXCEPTION( std::logic_error, CATCH_INTERNAL_LINEINFO << ": Internal Catch error: " << msg);
+#define CATCH_ERROR( msg ) \
+    throw CATCH_PREPARE_EXCEPTION( std::domain_error, msg )
+#define CATCH_ENFORCE( condition, msg ) \
+    do{ if( !(condition) ) CATCH_ERROR( msg ); } while(false)
+
+#endif // TWOBLUECUBES_CATCH_ENFORCE_H_INCLUDED