Does char_p::Box implement AsRef<str>? about safer_ffi HOT 4 CLOSED

from safer_ffi.

works on macOS

Hmm, that is weird: char_p::Box does indeed not implement AsRef<str> currently, for similary-ish reasons to stdlib's CStr not being AsRef<[u8]>: the operation is not constant (it needs to scan for the null-byte), and it is unclear whether the terminating null byte should be included in the output.

Note that I have no strong opinions on this, so I don't mind being convinced otherwise.

That being said, since char_p::Box does have an .into_string() method, which converts it into a String by reusing the allocation / in a zero-copy manner (it just .pop()s the terminating null byte), you could try to convert the char_p::Boxes into Strings beforehand if that is possible for you to do.

Otherwise you can also write your own wrapper type:

/// Same as `char_p::Box`, but with an `AsRef<str>` implementation which
/// includes
/// does not include
// (pick one)
/// the terminating null byte.
#[derive_ReprC] #[repr(transparent)] // <- if you want to use it instead of `char_p::Box` with `#[ffi_export]`
struct MyBoxedCString(char_p::Box);

impl AsRef<str> for MyBoxedCString {
    fn as_ref(self: &Self) -> &str {
        self.0.to_str()
        // pick one
        self.0.to_str_with_null()
    }
}

impl GenericCollectionShift<MyBoxedCString> for Shift {
}

from safer_ffi.

Hmm, there is an .into_string() operation, but no Into<String> impl. That one is very legitimate to add, so I may very well add it in the near future. Feel free to open an issue asking for it

from safer_ffi.

from safer_ffi.