# Change &'a T to Borrow\<'a,T\> and &'a mut T to BorrowMut\<'a,T\>
**URL:** https://internals.rust-lang.org/t/change-a-t-to-borrow-a-t-and-a-mut-t-to-borrowmut-a-t/1055
**Category:** ideas (deprecated)
**Created:** [December 20, 2014, 5:43pm UTC](https://internals.rust-lang.org/t/change-a-t-to-borrow-a-t-and-a-mut-t-to-borrowmut-a-t/1055 "2014-12-20T17:43:39Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@wooya](https://internals.rust-lang.org/u/wooya)
#### Post date: [December 20, 2014, 5:43pm UTC](https://internals.rust-lang.org/t/change-a-t-to-borrow-a-t-and-a-mut-t-to-borrowmut-a-t/1055/1 "2014-12-20T17:43:39Z")
Current Rust has not HKT (a.k.a Higher Kinded type) support.
With HKT being implemented in the future, we can write something like `fn produce_ref<'a,R,T>(a: &'a SomeType) -> R` , where `R` can be `Rc` or `Box` or `Arc` etc, but `R` cannot be an `&` because we cant represent `&` borrow in the `R` form.
So, what about change `&` borrow to `Borrow` and `&mut` to `BorrowMut`, and make `&`/`&mut` syntax be a syntax surgar of `Borrow`/`BorrowMut` ? It is more symmetric and HTK friendly.
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### Author:  [@arielb1](https://internals.rust-lang.org/u/arielb1)
#### Post date: [December 21, 2014, 10:56am UTC](https://internals.rust-lang.org/t/change-a-t-to-borrow-a-t-and-a-mut-t-to-borrowmut-a-t/1055/2 "2014-12-21T10:56:45Z")
This would be rather ugly. Also, there are other interesting types that you can’t put into a simple `A` form, for example `Rc>>` – when we implement HKT, we should probably allow using `type`-aliases as HKT-s, so you could simple have `type Borrow<'a, T> = &'a T;`.
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### Author:  [@system](https://internals.rust-lang.org/u/system)
#### Post date: [March 25, 2019, 8:23am UTC](https://internals.rust-lang.org/t/change-a-t-to-borrow-a-t-and-a-mut-t-to-borrowmut-a-t/1055/3 "2019-03-25T08:23:23Z")
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