NSProcessInfo-based iOS version check macro (iOS 8+)

iOSVersionCheck.h

#define INC_SYSTEM_VERSION(v)                      ((NSOperatingSystemVersion){v.majorVersion, v.minorVersion + 1, 0})
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) [[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:v]
#define SYSTEM_VERSION_LESS_THAN(v)                (!SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v))
#define SYSTEM_VERSION_EQUAL_TO(v)                 (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) && (!SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(INC_SYSTEM_VERSION(v))))
#define SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v)    (SYSTEM_VERSION_LESS_THAN(v) || SYSTEM_VERSION_EQUAL_TO(v))
#define SYSTEM_VERSION_GREATER_THAN(v)             (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) && (!SYSTEM_VERSION_EQUAL_TO(v)))

/*
// Manual logical check
NSOperatingSystemVersion v = (NSOperatingSystemVersion){8, 4, 0};
NSOperatingSystemVersion (^inc)(NSOperatingSystemVersion) = ^(NSOperatingSystemVersion v){
	return (NSOperatingSystemVersion){v.majorVersion, v.minorVersion + 1, 0};
};

BOOL greaterThanOrEqual = [[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:v];
BOOL lessThan = !greaterThanOrEqual;
BOOL equal = greaterThanOrEqual && ![[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:inc(v)];
BOOL lessThanOrEqual = lessThan || equal;
BOOL greaterThan = greaterThanOrEqual && !equal;

DLog(@"<= <  == >  >= | %@", [NSProcessInfo processInfo].operatingSystemVersionString);
DLog(@"%i  %i  %i  %i  %i", lessThanOrEqual, lessThan, equal, greaterThan, greaterThanOrEqual);
DLog(@"%i  %i  %i  %i  %i", SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v), SYSTEM_VERSION_LESS_THAN(v), SYSTEM_VERSION_EQUAL_TO(v), SYSTEM_VERSION_GREATER_THAN(v), SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v));
*/

iOSVersionCheck.swift

extension NSProcessInfo {

	@available(iOS 8.0, *)
	public func systemVersionGreaterThanOrEqualTo(version: NSOperatingSystemVersion) -> Bool {
		return isOperatingSystemAtLeastVersion(version)
	}

	@available(iOS 8.0, *)
	public func systemVersionGreaterThan(version: NSOperatingSystemVersion) -> Bool {
		return systemVersionGreaterThanOrEqualTo(version) && !systemVersionEqualTo(version)
	}

	@available(iOS 8.0, *)
	public func systemVersionEqualTo(version: NSOperatingSystemVersion) -> Bool {
		return (systemVersionGreaterThanOrEqualTo(version) && !systemVersionGreaterThanOrEqualTo(incrementSystemVersion(version)))
	}

	@available(iOS 8.0, *)
	public func systemVersionLessThan(version: NSOperatingSystemVersion) -> Bool {
		return !systemVersionGreaterThanOrEqualTo(version)
	}

	@available(iOS 8.0, *)
	public func systemVersionLessThanOrEqualTo(version: NSOperatingSystemVersion) -> Bool {
		return systemVersionLessThan(version) || systemVersionEqualTo(version)
	}

	/// Increment minor OS version and drop 'patch' version (e.g.: 8.1.1 -> 8.2.0)
	private func incrementSystemVersion(var version: NSOperatingSystemVersion) -> NSOperatingSystemVersion {
		version.minorVersion++
		version.patchVersion = 0
		return version
	}

}

/*
// Manual logical check
let v = NSOperatingSystemVersion(majorVersion: 8, minorVersion: 4, patchVersion: 0)

let greaterThanOrEqual = NSProcessInfo.processInfo().isOperatingSystemAtLeastVersion(v)
let lessThan = !greaterThanOrEqual
let equal = greaterThanOrEqual && !NSProcessInfo.processInfo().isOperatingSystemAtLeastVersion(incrementSystemVersion(v))
let lessThanOrEqual = lessThan || equal
let greaterThan = greaterThanOrEqual && !equal

dlog("<= <  == >  >= | \(NSProcessInfo.processInfo().operatingSystemVersionString)")
dlog("\(lessThanOrEqual ? 1 : 0)  \(lessThan ? 1 : 0)  \(equal ? 1 : 0)  \(greaterThan ? 1 : 0)  \(greaterThanOrEqual ? 1 : 0)")
dlog("\(NSProcessInfo.processInfo().systemVersionLessThanOrEqualTo(v) ? 1 : 0)  \(NSProcessInfo.processInfo().systemVersionLessThan(v) ? 1 : 0)  \(NSProcessInfo.processInfo().systemVersionEqualTo(v) ? 1 : 0)  \(NSProcessInfo.processInfo().systemVersionGreaterThan(v) ? 1 : 0)  \(NSProcessInfo.processInfo().systemVersionGreaterThanOrEqualTo(v) ? 1 : 0)")
*/