[spacechild1]

Smart pointers do not necessarily use reference counting. std::shared_ptr is reference counted, but std::unique_ptr is not. Needless to say that std::unique_ptr should always be the default choice and std::shared_ptr only used when actually needed.

[kps]

std::unique_ptr is reference counted, it's just that the count only goes up to BOOL_MAX instead of LONG_MAX.

[jb1991]

I think you’re making a joke, but reference counting is different than what a unique pointer does. (a destructor is not the same thing as a reference count, even if that reference count is limited as you suggest.)

[Joker_vD]

No, I don't think it's a joke. It's just that when your counter is limited to values of 0 and 1 only, you can optimize it so heavily it almost looks like a different thing entirely: binary semaphores are usually called mutexes, but they're still semaphores.

[kps]

It was a joke and not a joke, a joke with a kernel of truth.

But I only now just discovered that C23 is genuinely adding `BOOL_MAX`, which reminds me of the classic Fortran —

> The primary purpose of the DATA statement is to give names to constants; instead of referring to pi as 3.141592653589793 at every appearance, the variable PI can be given that value with a DATA statement and used instead of the longer form of the constant. This also simplifies modifying the program, should the value of pi change.

[jb1991]

But it’s not counted, that’s my point.

It’s getting quite pedantic to talk about ones and zeros in this context anyway.

[spacechild1]

Please show me the counter in std::unique_ptr :-)

[Joker_vD]

Since that counter can only have two values, it's storage is optimized and merged with the underlying raw pointer itself (not unlike Rust's null pointer optimization for enums): non-null value of the underlying pointer also serve to represent the counter's value of 1, and the null value serves to represent the counter's value of 0. The check to not under-decrement, for example, manifests as the null check before calling the deleter on the underlying pointer.

[spacechild1]

Sigh, I saw this coming. By this definition, every C++ object with a (non-trivial) destructor would be "reference counted". Sorry, but I am not interested in playing word games.