list.her.sh

Apple’s A7 chip famously moved to a 64-bit architecture. This ushered in an era of access to more memory* and a CGFloat type previously aliased to float newly redefined as double. Wait, what?

If you’re writing an iOS app that targets multiple architectures, you’ll want to use the proper CGFloat type for the current device’s architecture. You’ll also want to use the correct float or double versions of math functions like floor (double) or floorf (float).

Thanks to some preprocessor magic and the CGFLOAT_IS_DOUBLE define, we can construct some helpers that call the correct math function and return a number of the correct type for the current architecture. Behold, SPLFloat.h!

Update: One alternative to the below is tgmath.h, though it must be included before math.h. That can be challenging if you’re using CocoaPods.

// SPLFloat.h

@import Foundation;

#pragma once

CG_INLINE CGFLOAT_TYPE SPLFloat_floor(CGFLOAT_TYPE cgfloat)
{
#if CGFLOAT_IS_DOUBLE
	return floor(cgfloat);
#else
	return floorf(cgfloat);
#endif
}

CG_INLINE CGFLOAT_TYPE SPLFloat_ceil(CGFLOAT_TYPE cgfloat)
{
#if CGFLOAT_IS_DOUBLE
	return ceil(cgfloat);
#else
	return ceilf(cgfloat);
#endif
}

CG_INLINE CGFLOAT_TYPE SPLFloat_round(CGFLOAT_TYPE cgfloat)
{
#if CGFLOAT_IS_DOUBLE
	return round(cgfloat);
#else
	return roundf(cgfloat);
#endif
}

CG_INLINE CGFLOAT_TYPE SPLFloat_abs(CGFLOAT_TYPE cgfloat)
{
#if CGFLOAT_IS_DOUBLE
	return fabs(cgfloat);
#else
	return fabsf(cgfloat);
#endif
}

CG_INLINE CGFLOAT_TYPE SPLFloat_pow(CGFLOAT_TYPE cgfloat, 
                                    CGFLOAT_TYPE exp)
{
#if CGFLOAT_IS_DOUBLE
	return pow(cgfloat, exp);
#else
	return powf(cgfloat, exp);
#endif
}

* My kingdom for an iPhone with more than 1GB RAM.