Confusion due to Swift lacking implicit conversion of CGFloat

Question

Trying to do arithmetic in a function that returns `CGFloat, I get an error:

Couldn\'t find overload for \'/\' that accepts supplied arguments

Answer 1

This should fix the error:

func kDCControlDegreesToRadians(x : CGFloat) -> CGFloat
{
    return (CGFloat(M_PI) * (x) / 180.0)
}

The reason the error is occurring is because x is explicitly declared to be a CGFloat, while M_PI has the type CDouble, as seen in the declaration:

var M_PI: CDouble { get } /* pi             */

Because of this, you need to cast M_PI to type CGFloat so it matches the type of x (as I have done in the code above). This way, there is no conflict in operating on different types.

Note that, contrary to what is stated in other answers (and as @Cezar commented), you do not need to explicitly cast 180.0 to the CGFloat type, because it is a literal, and does not have an explicit type, so will automatically be converted to CGFloat without needing a manual cast.