Tracking issue for CString::{from_ptr, into_ptr}

[alexcrichton]

This is a tracking issue for the unstable cstr_memory feature in the standard library. These methods are likely ready to go as-is modulo naming. Their names should be consistent with Box::{from_raw, into_raw} (currently inconsistent).

cc #27768

[alexcrichton]

This feature is now entering its final comment period for stabilization.

I will post a PR soon for renaming these function to from_raw and into_raw.

[shepmaster]

renaming these function to from_raw and into_raw

Awesome! That makes sense to me.

[bluss]

This rename is important because CStr::from_ptr and CString::from_ptr are so different, but with similar names.

[bluss]

If you use CString::from_ptr on a non-rust allocated thing by mistake, you end up trying to reallocate string literals and things like that. See #27878.

[bluss]

We need to learn from these bugs. Premature dropping of CString leading to dangling pointers, and that some raw pointers transfer ownership and others are "borrowed". Can we use the type system better?

[shepmaster]

@bluss an interesting question. In my mind, once you hit a raw pointer, all bets are off and you have to manage everything yourself. Do you have any thoughts on how to improve that with types?