Re: [PATCH 1/4] rust: alloc: implement `Borrow` and `BorrowMut` for `Vec`
From: Benno Lossin
Date: Mon Jun 02 2025 - 16:21:29 EST
On Mon Jun 2, 2025 at 5:06 PM CEST, Boqun Feng wrote:
> On Mon, Jun 02, 2025 at 10:13:22AM +0900, Alexandre Courbot wrote:
>> 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> ...
Does that get rendered in the docs? If not, I don't think we should do
it.
---
Cheers,
Benno