如何在目标c中定义一个函数

Question

我想将此代码从Swift转换为Objective C：

typealias Completion = ([Media]?) -> Void

我已查看Stack Overflow帖子，但我没有看到答案。

Answer 1

struct LambdaContainer{ 
    std::function<void(void)> f;
    float x = 10;
}

struct MyClass{
    LambdaContainer c;

}
void someFunction(){
    MyClass ins;
    LambdaContainer cont;
    cont.f = [&cont](){
        // I want to modify 'x' of LambdaContainer that is inside MyClass

        cont.x = 10; // won't work because cont will be copy constructed
                     // and this cont might not exist anymore
    };
    ins.c = cont;
    aVectorSomewhere.push_back(ins);
}

Answer 2

typedef void (^CompletionBlock) (NSArray* array);