I have the following struct which I need an owned version of.

#[borrowme]
#[derive(Clone)]
pub struct Vector<'v, 't> {
    data: &'v [f32], // Or &'v Vec<f32>
    term: &'t str,
}

But I get the following error message:

 --> src/vector.rs:3:1
  |
3 | #[borrowme]
  | ^^^^^^^^^^^ expected `&[f32]`, found `Vec<_>`
  |
  = note: expected reference `&[f32]`
                found struct `Vec<_>`
  = note: this error originates in the attribute macro `borrowme` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `f32: borrowme::Borrow` is not satisfied
 --> src/vector.rs:3:1
  |
3 | #[borrowme]
  | ^^^^^^^^^^^ the trait `borrowme::Borrow` is not implemented for `f32`
  |

This introduces and adds support for deriving BorrowMut if mutable access is required. Mutable access is determined if a mutable reference is observed in the field type or if #[borrowme(mut)] is specified.

A type can either implement Borrow or BorrowMut, borrowed fields are supported for BorrowMut implementations but not vice versa.

Since compositional types do not have a mutable reference, the #[borrowme(mut)] attribute is required to make these work.

#[borrowme]
struct Inner<'a> {
    text: &'static str,
    lang: &'a mut String,
}

#[borrowme]
struct BorrowMutStruct<'a> {
    text: &'a str,
    #[borrowme(mut)]
    inner: Inner<'a>,
}

This replaces the #[borrowme(prefix = <ident>)] container attribute with #[borrowme(name = <ident>)] since the latter makes much more sense. There is very little value in overriding only part of the name if you're making the effort to override it anyways.