Is !! a safe way to convert to bool in C++?

Question

[This question is related to but not the same as this one.]

If I try to use values of certain types as boolean expressions, I get a warning. Rather than su

Answer 1

All valid techniques, all will generate the same code.

Personally, I just disable the warning so I can use the cleanest syntax. Casting to a bool is not something I'm worried about doing accidentally.