typedef block

double(^g)(double, double) = ^(double a, double b){

            double c = a +b ;

            return c;

        };

^(double a, double b) // the caret represents a block literal. This block takes two double parameters. Note we don't have to explicitly specify the return type

{

   double c = a + b;

   return c; //

}v

typedef double(^BinaryOpBlock_t)(double, double);

BinaryOpBlock_t operation_creator(int op)

{

   if (op == 0)

      return ^(double x, double y) { return x + y; }; // addition block

   if (op == 1)

      return ^(double x, double y) { return x * y; }; // multiplication block

// ... etc.

}

int main()

{

   BinaryOpBlock_t sum = operation_creator(0); // option '0' represents addition

   NSLog(@"sum of 5.5 and 1.3 is %f", sum(5.5, 1.3));

   NSLog(@"product of 3.3 and 1.0 is %f", operation_creator(1)(3.3, 1.0)); // cool, we've composed the function invocation and the block invocation!

}







typedef NS_ENUM(NSUInteger, MCSwipeTableViewCellState){

    MCSwipeTableViewCellStateNone = 0,

    MCSwipeTableViewCellState1,

    MCSwipeTableViewCellState2,

    MCSwipeTableViewCellState3,

    MCSwipeTableViewCellState4

};