./BinauralBeats.h:41:3: warning: control reaches end of non-void function [-Wreturn-type]

Index: BinauralBeats.h
--- BinauralBeats.h.orig
+++ BinauralBeats.h
@@ -38,6 +38,7 @@ class AP{//allpass
 		};
 		REALTYPE set(REALTYPE a_){
 			a=a_*a_;
+			return a;
 		};
 	private:
 		REALTYPE in1,in2,out1,out2;