The Perfect Singleton

Singleton.m

A singleton which you can drop into any class without having to change a line of code no matter the class, no macros needed.

//.h
+ (instancetype)sharedRuntimeController;

//.m

+ (instancetype)sharedRuntimeController
{
    static id _sharedRuntimeController = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _sharedRuntimeController = [[[self class] alloc] init];
    });
    
    return _sharedRuntimeController;
}