Re: [PATCH 1/4] rust: alloc: implement `Borrow` and `BorrowMut` for `Vec`
From: Boqun Feng
Date: Mon Jun 02 2025 - 11:31:06 EST
On Mon, Jun 02, 2025 at 10:13:22AM +0900, Alexandre Courbot wrote:
> Hi Benno,
>
> On Mon Jun 2, 2025 at 1:11 AM JST, Benno Lossin wrote:
> > On Sun Jun 1, 2025 at 5:00 AM CEST, Alexandre Courbot wrote:
> >> Implement these two common traits, which allow generic types to store
> >> either an owned value or a reference to it.
> >
> > I don't understand the second part of the sentence.
>
> I want to say that Borrow allows you to do something like:
>
> struct Foo<B: Borrow<u32>>(B);
>
> // `foo1` owns its value...
> let foo1 = Foo(0x12);
>
> let i = 0x24;
> // ... but `foo2` just borrows it, subject to the lifetime of `i`.
> let foo2 = Foo(&i);
>
> And the implementations in this series also let you do:
>
> // `foo3`'s value is owned, but heap-allocated
> let foo3 = Arc::new(KBox::new(0x56, GFP_KERNEL)?);
>
> let j = Arc::new(0x78, GFP_KERNEL)?;
> // `foo4`'s value is shared and its lifetime runtime-managed.
> let foo4 = Foo(j.clone());
Maybe you could put these in the "# Examples" section before impl
blocks. E.g
/// # Examples
/// ```
/// <you case above>
/// ```
impl<T, A> Borrow<[T]> for Vec<T, A> ...
Regards,
Boqun