Why doesn't this work?

[IndieExe]

//Why can i do this to de-allocate from the heap,
char * p = new char[20];
void *i = p;
delete[](char*)i;

//but not this?
//Can you explain?
char * p = new char[20];
unsigned long x = (unsigned long)p;
void *i = i;
delete[](char*)i;

[vlad from moscow]

Is it a typo?

void *i = i;

[IndieExe]

Is it a typo?

Yes, and not it works. Thank you.

char * p = new char[20];
unsigned long x = (unsigned long)p;
void *i = (void*)x;
delete[](char*)i;