GCC Lexical Closures

closure.c

#include <stdio.h>

void sayHello(void (*log)(char*))
{
	log("Hello, world!");
}

int main(int argc, char** argv)
{
	void log(char* message)
	{
		printf("%s: %s\n", argv[0], message);
	}
	
	sayHello(log);
	
	return 0;
}