Messages in this thread | | | Date | Thu, 30 Mar 2023 17:00:48 +0200 | Subject | Re: [PATCH v3 08/13] rust: init: add `stack_pin_init!` macro | From | Alice Ryhl <> |
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On 3/30/23 00:33, y86-dev@protonmail.com wrote: > From: Benno Lossin <y86-dev@protonmail.com> > > The `stack_pin_init!` macro allows pin-initializing a value on the > stack. It accepts a `impl PinInit<T, E>` to initialize a `T`. It allows > propagating any errors via `?` or handling it normally via `match`. > > Signed-off-by: Benno Lossin <y86-dev@protonmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
> --- > +#[macro_export] > +macro_rules! stack_pin_init { > + (let $var:ident $(: $t:ty)? = $val:expr) => { > + let mut $var = $crate::init::__internal::StackInit$(::<$t>)?::uninit(); > + let mut $var = { > + let val = $val; > + unsafe { $crate::init::__internal::StackInit::init(&mut $var, val) } > + }; > + }; > + (let $var:ident $(: $t:ty)? =? $val:expr) => { > + let mut $var = $crate::init::__internal::StackInit$(::<$t>)?::uninit(); > + let mut $var = { > + let val = $val; > + unsafe { $crate::init::__internal::StackInit::init(&mut $var, val)? } > + }; > + }; > +}
This will be inconvenient to use if the initializer is infallible and is used inside an infallible function. However, I'm not sure what a better alternative would be. Perhaps we should have three variants?
Also, maybe a `<-` rather than `=` would be more consistent?
Anyway, I don't think this should block the PR. We can revisit it later if it becomes a problem.
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