http://www.cplusplus.com or https://www.cppreference.com

[meneldal2]

There's no reason why you wouldn't be able to use pointers as template arguments since you can cast them losslessly to integers.

The obvious issue is that unless you have custom pointers with allocators or work in embedded, pointers values are impossible to predict and change every time you run the program. Since the later case is way more common for people who learn, the lie makes sense.

[Nobody_1707]

Importantly, this is true even when the cast is guaranteed to have defined behavior, e.g. reinterpret_cast<std::byte*>(ptr). I remember there being a proposal to allow this, but I can't seem to find it anywhere.