是否可以像在C语言中一样在ObjC中使用函数和函数指针？

Question

I am familiar with C and am now learning Objective-C.

I often use function pointers

void (*callback)(int*restrict, char*restrict)

Will that be usable in Objective-C? Especially in structs, like so:

struct mytype myvar = {
    .first = myCallback;
    .second = myCallback2;
} 

Also, I wish to have function prototypes like

void function(int * restrict a, char * restrict b);
char * function (char * a);
...

Are there no problems with using this style?

Answer 1

Clang (the default compiler used by Xcode) claims C11 support for Objective C (See Language Compatibility ).

This means function pointers, restrict, structs, and declarations will all work as you would expect.

One word of advice: don't fight the system; it will create more work for yourself and less reliable software for your users. Programmers should be like water.

Empty your mind, be formless, shapeless — like water. Now you put water in a cup, it becomes the cup; You put water into a bottle it becomes the bottle; You put it in a teapot it becomes the teapot. Now water can flow or it can crash. Be water, my friend.

— Bruce Lee

Answer 2

Yes.

You can use any C strategy that you choose in your Objective-C app. You will still have to write some Objective-C in order to start your UIApplication (or use a third-party tool to do it for you).

One thing to keep in mind, though, is that int will be a different length depending on the machine and you should explicitly choose int32_t or int16_t or int8_t if you really don't want to use the NSInteger typedef that abstracts this machine difference.