Changes in src/AST/Node.hpp [4864a73:b7d92b96]

File:

• src/AST/Node.hpp (modified) (3 diffs)

src/AST/Node.hpp

@@ -18 +18 @@
 #include <cassert>
 #include <iosfwd>
+#include <type_traits> // for remove_reference
 
 #include "Common/ErrorObjects.h"  // for SemanticErrorException
@@ -82 +83 @@
 };
 
-// Mutate a node, non-member function to avoid static type
-// problems and be able to use auto return
+/// Mutate a node, non-member function to avoid static type
+/// problems and be able to use auto return
 template<typename node_t>
 node_t * mutate( const node_t * node ) {
@@ -95 +96 @@
         );
         return node->clone();
+}
+
+/// Mutate a node field (only clones if not equal to existing value)
+template<typename node_t, typename field_t>
+const node_t * mutate_field( 
+        const node_t * node, 
+        typename std::remove_const<typename std::remove_reference<field_t>::type>::type node_t::* field,
+        field_t&& val 
+) {
+        if ( node->*field == val ) return node;
+        
+        node_t * ret = mutate( node );
+        ret->*field = std::forward< field_t >( val );
+        return ret;
 }