#import "NSString+GSVersionComparator.h"

// Compare iOS versions
if ([[UIDevice currentDevice].systemVersion gs_versionLessThan:@"7.0"]) {
    // Do something specific for iOS 6 and below 
}

// Compare arbitrary version strings
NSURL *apiEndpoint = [NSURL URLWithString:@"http://example.com/2.0/resource"];
NSString *versionComponent = apiEndpoint.pathComponents[1];

NSString *supportedAPIVersion = @"2";

if ([versionComponent gs_versionEquals:supportedAPIVersion]) {
    // Your client supports this api version, it's safe to proceed
}

// Compare complex version strings like '1' and '1.0-0'
BOOL test = [@"1" gs_versionEquals:@"1.0-0"]; // Returns YES
BOOL test = [@"1.0.b" gs_versionGreaterThan:@"1.0.a"]; // Returns YES
BOOL test = [@"1.0" gs_versionLessThan:@"1.0-SNAPSHOT"]; // Returns NO