diff mbox series

[v1,27/28] rust: types: add `Either` type

Message ID	20221110164152.26136-28-ojeda@kernel.org
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: Miguel Ojeda <ojeda@kernel.org> To: Miguel Ojeda <ojeda@kernel.org>, Wedson Almeida Filho <wedsonaf@gmail.com>, Alex Gaynor <alex.gaynor@gmail.com>, Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>, =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com> Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev Subject: [PATCH v1 27/28] rust: types: add `Either` type Date: Thu, 10 Nov 2022 17:41:39 +0100 Message-Id: <20221110164152.26136-28-ojeda@kernel.org> In-Reply-To: <20221110164152.26136-1-ojeda@kernel.org> References: <20221110164152.26136-1-ojeda@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Rust core additions \| [v1,00/28] Rust core additions [v1,01/28] rust: prelude: split re-exports into groups [v1,02/28] rust: print: add more `pr_!` levels [v1,03/28] rust: print: add `pr_cont!` macro [v1,04/28] rust: samples: add `rust_print` example [v1,05/28] rust: macros: add `concat_idents!` proc macro [v1,06/28] rust: macros: add `#[vtable]` proc macro [v1,07/28] rust: macros: take string literals in `module!` [v1,08/28] rust: error: declare errors using macro [v1,09/28] rust: error: add codes from `errno-base.h` [v1,10/28] rust: error: add `From` implementations for `Error` [v1,11/28] rust: prelude: add `error::code::` constant items [v1,12/28] rust: alloc: add `RawVec::try_with_capacity_in()` constructor [v1,13/28] rust: alloc: add `Vec::try_with_capacity{,_in}()` constructors [v1,14/28] rust: str: add `BStr` type [v1,15/28] rust: str: add `b_str!` macro [v1,16/28] rust: str: add `CStr` type [v1,17/28] rust: str: implement several traits for `CStr` [v1,18/28] rust: str: add `CStr` unit tests [v1,19/28] rust: str: add `c_str!` macro [v1,20/28] rust: str: add `Formatter` type [v1,21/28] rust: str: add `CString` type [v1,22/28] rust: str: add `fmt!` macro [v1,23/28] rust: std_vendor: add `dbg!` macro based on `std`'s one [v1,24/28] rust: static_assert: add `static_assert!` macro [v1,25/28] rust: add `build_error` crate [v1,26/28] rust: build_assert: add `build_{error,assert}!` macros [v1,27/28] rust: types: add `Either` type [v1,28/28] rust: types: add `Opaque` type

Commit Message

Miguel Ojeda Nov. 10, 2022, 4:41 p.m. UTC

  From: Wedson Almeida Filho <wedsonaf@gmail.com>

Introduce the new `types` module of the `kernel` crate with
`Either` as its first type.

`Either<L, R>` is a sum type that always holds either a value
of type `L` (`Left` variant) or `R` (`Right` variant).

For instance:

    struct Executor {
        queue: Either<BoxedQueue, &'static Queue>,
    }

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/lib.rs   |  1 +
 rust/kernel/types.rs | 12 ++++++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 rust/kernel/types.rs

Comments

Wei Liu Nov. 14, 2022, 2:32 p.m. UTC | #1

On Thu, Nov 10, 2022 at 05:41:39PM +0100, Miguel Ojeda wrote:
> From: Wedson Almeida Filho <wedsonaf@gmail.com>
> 
> Introduce the new `types` module of the `kernel` crate with
> `Either` as its first type.
> 
> `Either<L, R>` is a sum type that always holds either a value
> of type `L` (`Left` variant) or `R` (`Right` variant).
> 
> For instance:
> 
>     struct Executor {
>         queue: Either<BoxedQueue, &'static Queue>,
>     }
> 
> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
> [Reworded, adapted for upstream and applied latest changes]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Wei Liu <wei.liu@kernel.org>

diff mbox series

Patch

diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index a3abc110ff97..53040fa9e897 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -31,6 +31,7 @@  mod static_assert;
 #[doc(hidden)]
 pub mod std_vendor;
 pub mod str;
+pub mod types;
 
 #[doc(hidden)]
 pub use bindings;
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
new file mode 100644
index 000000000000..3b0c44769708
--- /dev/null
+++ b/rust/kernel/types.rs
@@ -0,0 +1,12 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+//! Kernel types.
+
+/// A sum type that always holds either a value of type `L` or `R`.
+pub enum Either<L, R> {
+    /// Constructs an instance of [`Either`] containing a value of type `L`.
+    Left(L),
+
+    /// Constructs an instance of [`Either`] containing a value of type `R`.
+    Right(R),
+}