class myClass{
    ...
    public:
    T1 foo(T2 x){T1 y; /*something*/ return y;};
}

myClass obj;
T1 a = obj.foo(x);  //<--

myClass obj;
obj.foo(x);   //<--

T1 a = obj.foo(x);
obj.foo(x);

T1 a = obj.foo(x);
obj.foo(x);

T1 foo(T2 x) __attribute__ ((warn_unused_result));