#import "FDStackViewExtensions.h"

#import <objc/runtime.h>

@implementation NSMapTable (FDAllObjects)

- (NSArray *)fd_allObjects {

return self.objectEnumerator.allObjects ?: @[];

}

@implementation NSLayoutConstraint (FDStackViewExtensions)

+ (void)load {

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

// iOS6 patch

if(!class_getProperty(self, "identifier")) {

SEL getterSelector = sel_registerName("identifier");

class_addMethod(self, getterSelector, imp_implementationWithBlock(^(id self) {

return objc_getAssociatedObject(self, getterSelector);

}), "@@");

class_addMethod(self, sel_registerName("setIdentifier:"), imp_implementationWithBlock(^(id self, id value) {

objc_setAssociatedObject(self, getterSelector, value, OBJC_ASSOCIATION_COPY_NONATOMIC);

}), "v@:@");

}

});

}

@implementation NSArray (FDCarAndCdr)

- (id)car {

return self.firstObject;

}

- (NSArray *)cdr {

if (self.count <= 1) return nil;

return [self subarrayWithRange:(NSRange){1, self.count - 1}];

}