What does “control reaches end of non-void function” mean?

Question

I\'ve been getting strange compiler errors on this binary search algorithm. I get a warning that control reaches end of non-void function. What does this mean?<

Answer 1

Always build with at least minimal optimization. With -O0, all analysis that the compiler could use to determine that execution cannot reach the end of the function has been disabled. This is why you're seeing the warning. The only time you should ever use -O0 is for step-by-line debugging, which is usually not a good debugging approach anyway, but it's what most people who got started with MSVC learned on...