Question

I have a property that’s a double in C++/CLI that I need to cast to an integer, but the compiler gives me a warning (c4244) when I do so. For example:

//"Value" is a double
int newValue = (int)(control->Value); //C4244

I understand that the compiler isn’t happy because a double might be larger than an int can hold, but this particular control is guaranteed to be a value from 1 to 10, so I know that it will be okay. Can I eliminate this warning somehow?

Answer 1

The compiler is warning you not just you might get out of range, but that you might lose information (It needs to round up the number somehow, and is afraid to do it by its own).

Use floor() to tell it you know what you’re doing:

int newValue = floor(control->Value); 

Or you could cast explicitly just to tell the compiler that there’s nothing implicit going on, and you know what you’re doing:

int newValue = (int)(float)(control->Value);