Why use functions like CGRectMake?

Question

I'm curious why functions like CGRectMake and CGPointMake exist and are widely used. when, instead, you can do:

(CGRect){{x, y}, {width, height}}

surely this is more efficient (though I'm guessing not by much) as there is no function call?

Also you can set the origin and size like:

 (CGRect){origin, size}

and as a mixture:

 (CGRect){origin, {width, height}}

What is the reason for not using this, and preferring the Make functions?

Answer 1

It isn't more efficient, actually. The CGRectMake function (and others) are declared as static inline, which means the compiler copy pastes the function code straight into every place it's used:

CG_INLINE CGRect
CGRectMake(CGFloat x, CGFloat y, CGFloat width, CGFloat height)

where

#  define CG_INLINE static inline

You go from

// code
CGRect myRect = CGRectMake(1,2,3,4);
// code

to

// code
CGRect myRect;
myRect.origin.x = 1; myRect.origin.y = 2;
myRect.size.width = 3; myRect.size.height = 4;

which in principle is no different from

CGRect myRect = (CGRect){1,2,3,4};

after compiler optimizations and such.

As said above you add a dependency on CGRect being a struct of 4 numbers aligned a certain way as opposed to using a function that has more guarantee to it.