g++ How to get warning on ignoring function return value

Question

lint produces some warning like:

foo.c XXX Warning 534: Ignoring return value of function bar()

From the lint manual

Answer 1

I solved the problem like this:

#define ignore_result(x) if (x) {}

then instead of (void)foo() use ignore_result(foo())

Then the code compiles with -Wall just fine.