Index: src/ResolvExpr/Alternative.cc
===================================================================
--- src/ResolvExpr/Alternative.cc	(revision bd4f2e9b269f4ba6094575b830cab685e3a1d075)
+++ src/ResolvExpr/Alternative.cc	(revision 50fede9f33f5fed7be2e9577759525a2353dd0c9)
@@ -27,5 +27,5 @@
 
 namespace ResolvExpr {
-	Alternative::Alternative() : cost( Cost::zero ), cvtCost( Cost::zero ), expr( 0 ) {}
+	Alternative::Alternative() : cost( Cost::zero ), cvtCost( Cost::zero ), expr( nullptr ) {}
 
 	Alternative::Alternative( Expression *expr, const TypeEnvironment &env, const Cost& cost )
@@ -48,5 +48,5 @@
 	}
 
-	Alternative::Alternative( Alternative && other ) : cost( other.cost ), cvtCost( other.cvtCost ), expr( other.expr ), env( other.env ) {
+	Alternative::Alternative( Alternative && other ) : cost( other.cost ), cvtCost( other.cvtCost ), expr( other.expr ), env( std::move( other.env ) ) {
 		other.expr = nullptr;
 	}
@@ -58,5 +58,5 @@
 		cvtCost = other.cvtCost;
 		expr = other.expr;
-		env = other.env;
+		env = std::move( other.env );
 		other.expr = nullptr;
 		return *this;