Syntax to define a Block that takes a Block and returns a Block in Objective-C

Question

I find in Apple\'s document Working with Blocks that the syntax to define a block that returns the result of multiplying two values:

double (^multiplyTwoValu         


        

Answer 1

Obj-C block syntax is pretty hard to read, this can be simplified a bit with the use of typedefs.

//setup
typedef void (^ReturnedBlock)(void);
ReturnedBlock retBlock = ^void(void){};

typedef void (^ParamBlock)(void);
ParamBlock paramBlock = ^void(void){};

//the thing you want to do
ReturnedBlock (^someBlock)(ParamBlock) = ^ReturnedBlock(ParamBlock param){

    return retBlock;
};

//perform the block
ReturnedBlock r = someBlock(paramBlock);