Why do some c++ compilers let you take the address of a literal?

Question

A C++ compiler that I will not name lets you take the address of a literal, int *p = &42;

Clearly 42 is an r-value and most compilers refuse to do so.

W

Answer 1

It effectively requires the compiler to initialize a pointer with the address of an integer with the value 42

Then why, in some compilers, we can't take the address of a literal directly ?

int* ptr = &10;

The reference:

int& ref = 10;

is almost the same thing as a pointer, though...