The problem in your thinking is that you say "it can eventually bottom out by returning NULL". But you don't tell the compiler that. You have to end the recurs

The problem in your thinking is that you say "it can eventually bottom out by returning NULL". But you don't tell the compiler that. You have to end the recursion somewhere. Fortunately, you can just use an equivalent type. typedef void^(^func_ptr0)( void^ ); typedef func_ptr0 (^func_ptr)( funcptr0 ); func_ptr foo( func_ptr a ) { return a; } void main() { func_ptr ^p = foo; } There's really no reason to keep expanding it. If you're suggesting that using a void^ is not allowed, then that's like suggesting that you can't return NULL.