Can I boost::bind() to an Objective C function? - objective-c

Question

I have no idea if this is possible, but if it is, what would the syntax look like?
If not possible, why not?

Answer 1

You should be able to bind to a message implementation (IMP), which are just plain C functions with two hidden parameters, self and _cmd of types id and SEL respectively.
EDIT: Just tested the following complete example, and it appears to work.
#include <stdio.h>
#include <boost/bind.hpp>
#include <Foundation/NSObject.h>
#interface MyClass : NSObject
{
}
-(int) doSomething:(int)arg;
#end
#implementation MyClass
-(int) doSomething:(int)arg
{
printf("doSomething: self=0x%08x _cmd=0x%08x\n", self, _cmd);
return arg + 1;
}
#end
int main(void)
{
MyClass *myObj = [[MyClass alloc] init], *otherObj = [[MyClass alloc] init];
typedef int (*MyFunc)(id, SEL, int);
SEL doSomething_sel = #selector(doSomething:);
MyFunc doSomething_impl = (MyFunc)[myObj methodForSelector:doSomething_sel];
// bind self & _cmd arguments:
// calls [myObj doSomething:x]
int result = boost::bind(doSomething_impl, myObj, doSomething_sel, _1)(14);
printf("result1: %d\n", result);
// bind _cmd & arg:
// calls [otherObj doSomething:3]
result = boost::bind(doSomething_impl, _1, doSomething_sel, 42)(otherObj);
printf("result2: %d\n", result);
return 0;
}
With GNUstep, compile as:
gcc objcbind.mm -o objcbind -I/usr/include/GNUstep -lobjc -lstdc++ -lgnustep-base
On Mac OS X, compile as:
gcc objcbind.mm -o objcbind -framework Foundation -lstdc++
Output:
doSomething: self=0x01a85f70 _cmd=0x00602220
result1: 15
doSomething: self=0x01a83d70 _cmd=0x00602220
result2: 43