test.m

// clang test.m -framework Foundation -otest -g && ./test
#include <stdio.h>
#include <objc/message.h>
#include <Foundation/Foundation.h>

int main ()
{
	NSLog (@"64bit: %i", sizeof (void *) == 8);
	NSString *str = [NSString alloc];

	// crashes:
	// str = objc_msgSend (str, @selector (initWithFormat:arguments:), @"%d", 123);

	// crashes:
	// void *array[1];
	// array [0] = @"test";
	//str = objc_msgSend (str, @selector (initWithFormat:arguments:), @"%@", array);

	// works:
	str = objc_msgSend (str, @selector (initWithFormat:), @"%@", @"test");

	NSLog (@"%@", str);
	return 0;
}