It just occurred to me That I don't know how to initialize a pointer to pointer from a non pointer value with one statement in C++:
int a = 1;
int** ppa = &&a; //Does not compile
int** ppa = &(&a); //Does not compile
int* pa = &a; //Works but is a
int** ppa = &pa; //Two step solution
Am I missing something, is the two statement the one and only way to do it?
You want a pointer (call it PP) to a pointer (call it P)?
Then P must actually exist. Which means you must declare it.
Of course the compiler will fail at &&a - because you can't take the address of an address. You can take the address of a pointer - but you'll have to declare the pointer first.
Thus:
int a = 1;
int *P = &a;
int **PP = &P;
An address is a number. It only has an address of its own if it is held in a variable, i.e. a pointer. So
int *i1 = &a;
makes sense, but
int **i2 = &&a;
makes no sense. However
int **i2 = &i1;
does make sense. Make sense?