Index: src/SynTree/DeclReplacer.cc
===================================================================
--- src/SynTree/DeclReplacer.cc	(revision 172d9342f6b4a7736c11455e65aaff4ec00d647a)
+++ src/SynTree/DeclReplacer.cc	(revision 933f32f2ae9703d54327e4727aceb5746433092d)
@@ -38,4 +38,16 @@
 			void previsit( TypeInstType * inst );
 		};
+
+		/// Mutator that replaces uses of declarations with arbitrary expressions, according to the supplied mapping
+		struct ExprDeclReplacer {
+		private:
+			const ExprMap & exprMap;
+			bool debug;
+		public:
+			ExprDeclReplacer( const ExprMap & exprMap, bool debug = false );
+
+			// replace variable with new node from expr map
+			Expression * postmutate( VariableExpr * varExpr );
+		};
 	}
 
@@ -53,4 +65,9 @@
 		DeclMap declMap;
 		replace( node, declMap, typeMap, debug );
+	}
+
+	void replace( BaseSyntaxNode *& node, const ExprMap & exprMap, bool debug ) {
+		PassVisitor<ExprDeclReplacer> replacer( exprMap, debug );
+		node = maybeMutate( node, replacer );
 	}
 
@@ -79,4 +96,19 @@
 			}
 		}
+
+		ExprDeclReplacer::ExprDeclReplacer( const ExprMap & exprMap, bool debug ) : exprMap( exprMap ), debug( debug ) {}
+
+		Expression * ExprDeclReplacer::postmutate( VariableExpr * varExpr ) {
+			if ( exprMap.count( varExpr->var ) ) {
+				Expression * replacement = exprMap.at( varExpr->var )->clone();
+				if ( debug ) {
+					std::cerr << "replacing variable reference: " << (void*)varExpr->var << " " << varExpr->var << " with " << (void*)replacement << " " << replacement << std::endl;
+				}
+				std::swap( varExpr->env, replacement->env );
+				delete varExpr;
+				return replacement;
+			}
+			return varExpr;
+		}
 	}
 } // namespace VarExprReplacer
Index: src/SynTree/DeclReplacer.h
===================================================================
--- src/SynTree/DeclReplacer.h	(revision 172d9342f6b4a7736c11455e65aaff4ec00d647a)
+++ src/SynTree/DeclReplacer.h	(revision 933f32f2ae9703d54327e4727aceb5746433092d)
@@ -26,8 +26,19 @@
 	typedef std::map< DeclarationWithType *, DeclarationWithType * > DeclMap;
 	typedef std::map< TypeDecl *, TypeDecl * > TypeMap;
+	typedef std::map< DeclarationWithType *, Expression * > ExprMap;
 
 	void replace( BaseSyntaxNode * node, const DeclMap & declMap, bool debug = false );
 	void replace( BaseSyntaxNode * node, const TypeMap & typeMap, bool debug = false );
 	void replace( BaseSyntaxNode * node, const DeclMap & declMap, const TypeMap & typeMap, bool debug = false );
+
+	void replace( BaseSyntaxNode *& node, const ExprMap & exprMap, bool debug = false);
+	template<typename T>
+		void replace( T *& node, const ExprMap & exprMap, bool debug = false ) {
+		if ( ! node ) return;
+		BaseSyntaxNode * arg = node;
+		replace( arg, exprMap, debug );
+		node = dynamic_cast<T *>( arg );
+		assertf( node, "DeclReplacer fundamentally changed the type of its argument." );
+	}
 }
 
Index: src/SynTree/Expression.cc
===================================================================
--- src/SynTree/Expression.cc	(revision 172d9342f6b4a7736c11455e65aaff4ec00d647a)
+++ src/SynTree/Expression.cc	(revision 933f32f2ae9703d54327e4727aceb5746433092d)
@@ -538,11 +538,8 @@
 	assert( callExpr );
 	assert( callExpr->result );
-	set_result( callExpr->get_result()->clone() );
+	set_result( callExpr->result->clone() );
 }
 
 ImplicitCopyCtorExpr::ImplicitCopyCtorExpr( const ImplicitCopyCtorExpr & other ) : Expression( other ), callExpr( maybeClone( other.callExpr ) ) {
-	cloneAll( other.tempDecls, tempDecls );
-	cloneAll( other.returnDecls, returnDecls );
-	cloneAll( other.dtors, dtors );
 }
 
@@ -550,7 +547,4 @@
 	set_env( nullptr ); // ImplicitCopyCtorExpr does not take ownership of an environment
 	delete callExpr;
-	deleteAll( tempDecls );
-	deleteAll( returnDecls );
-	deleteAll( dtors );
 }
 
@@ -558,9 +552,4 @@
 	os <<  "Implicit Copy Constructor Expression: " << std::endl << indent+1;
 	callExpr->print( os, indent+1 );
-	os << std::endl << indent << "... with temporaries:" << std::endl;
-	printAll( tempDecls, os, indent+1 );
-	os << std::endl << indent << "... with return temporaries:" << std::endl;
-	printAll( returnDecls, os, indent+1 );
-	Expression::print( os, indent );
 }
 
Index: src/SynTree/Expression.h
===================================================================
--- src/SynTree/Expression.h	(revision 172d9342f6b4a7736c11455e65aaff4ec00d647a)
+++ src/SynTree/Expression.h	(revision 933f32f2ae9703d54327e4727aceb5746433092d)
@@ -593,19 +593,9 @@
 class ImplicitCopyCtorExpr : public Expression {
 public:
-	ApplicationExpr * callExpr;
-	std::list< ObjectDecl * > tempDecls;
-	std::list< ObjectDecl * > returnDecls;
-	std::list< Expression * > dtors;
+	ApplicationExpr * callExpr = nullptr;
 
 	ImplicitCopyCtorExpr( ApplicationExpr * callExpr );
 	ImplicitCopyCtorExpr( const ImplicitCopyCtorExpr & other );
 	virtual ~ImplicitCopyCtorExpr();
-
-	ApplicationExpr * get_callExpr() const { return callExpr; }
-	void set_callExpr( ApplicationExpr * newValue ) { callExpr = newValue; }
-
-	std::list< ObjectDecl * > & get_tempDecls() { return tempDecls; }
-	std::list< ObjectDecl * > & get_returnDecls() { return returnDecls; }
-	std::list< Expression * > & get_dtors() { return dtors; }
 
 	virtual ImplicitCopyCtorExpr * clone() const { return new ImplicitCopyCtorExpr( * this ); }