diff options
author | Andrew Walbran <qwandor@google.com> | 2021-12-02 11:49:30 +0000 |
---|---|---|
committer | Andrew Walbran <qwandor@google.com> | 2021-12-08 12:25:11 +0000 |
commit | cbd0311724eb8382bda7efb20d2131be0ad835c4 (patch) | |
tree | 2df8e61d06b48bf2b93ef276e8e7d4bdb7f7ded3 | |
parent | fb5796063541e66beca5e32e77fde1e0c7368e58 (diff) | |
download | enumn-cbd0311724eb8382bda7efb20d2131be0ad835c4.tar.gz |
Initial import
enumn was previously included in crosvm, now they are using the
crates.io crate instead so we need to import it into AOSP.
Bug: 207770431
Bug: 209654193
Test: m crosvm
Change-Id: Ic8a6ec3afa43811e54fa87d95d4f9eaaa58d9e2c
-rw-r--r-- | .cargo_vcs_info.json | 5 | ||||
-rw-r--r-- | .github/workflows/ci.yml | 21 | ||||
-rw-r--r-- | .gitignore | 3 | ||||
-rw-r--r-- | Android.bp | 18 | ||||
-rw-r--r-- | Cargo.toml | 35 | ||||
-rw-r--r-- | Cargo.toml.orig | 21 | ||||
l--------- | LICENSE | 1 | ||||
-rw-r--r-- | LICENSE-APACHE | 201 | ||||
-rw-r--r-- | LICENSE-MIT | 23 | ||||
-rw-r--r-- | METADATA | 20 | ||||
-rw-r--r-- | MODULE_LICENSE_APACHE2 | 0 | ||||
-rw-r--r-- | OWNERS | 1 | ||||
-rw-r--r-- | README.md | 110 | ||||
-rw-r--r-- | cargo2android.json | 9 | ||||
-rw-r--r-- | src/lib.rs | 199 |
15 files changed, 667 insertions, 0 deletions
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json new file mode 100644 index 0000000..ea3dd4d --- /dev/null +++ b/.cargo_vcs_info.json @@ -0,0 +1,5 @@ +{ + "git": { + "sha1": "30565e34c2a6e9ded85d27350b8a6c1e6207eb2c" + } +} diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml new file mode 100644 index 0000000..385cd8e --- /dev/null +++ b/.github/workflows/ci.yml @@ -0,0 +1,21 @@ +name: CI + +on: + push: + pull_request: + schedule: [cron: "40 1 * * *"] + +jobs: + test: + name: Rust ${{matrix.rust}} + runs-on: ubuntu-latest + strategy: + fail-fast: false + matrix: + rust: [nightly, beta, stable, 1.31.0] + steps: + - uses: actions/checkout@v2 + - uses: dtolnay/rust-toolchain@master + with: + toolchain: ${{matrix.rust}} + - run: cargo test diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..6936990 --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +/target +**/*.rs.bk +Cargo.lock diff --git a/Android.bp b/Android.bp new file mode 100644 index 0000000..e613d58 --- /dev/null +++ b/Android.bp @@ -0,0 +1,18 @@ +// This file is generated by cargo2android.py --config cargo2android.json. +// Do not modify this file as changes will be overridden on upgrade. + + + +rust_proc_macro { + name: "libenumn", + crate_name: "enumn", + cargo_env_compat: true, + cargo_pkg_version: "0.1.3", + srcs: ["src/lib.rs"], + edition: "2018", + rustlibs: [ + "libproc_macro2", + "libquote", + "libsyn", + ], +} diff --git a/Cargo.toml b/Cargo.toml new file mode 100644 index 0000000..e68e67d --- /dev/null +++ b/Cargo.toml @@ -0,0 +1,35 @@ +# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO +# +# When uploading crates to the registry Cargo will automatically +# "normalize" Cargo.toml files for maximal compatibility +# with all versions of Cargo and also rewrite `path` dependencies +# to registry (e.g., crates.io) dependencies +# +# If you believe there's an error in this file please file an +# issue against the rust-lang/cargo repository. If you're +# editing this file be aware that the upstream Cargo.toml +# will likely look very different (and much more reasonable) + +[package] +edition = "2018" +name = "enumn" +version = "0.1.3" +authors = ["David Tolnay <dtolnay@gmail.com>"] +description = "Convert number to enum" +documentation = "https://docs.rs/enumn" +readme = "README.md" +license = "MIT OR Apache-2.0" +repository = "https://github.com/dtolnay/enumn" +[package.metadata.docs.rs] +targets = ["x86_64-unknown-linux-gnu"] + +[lib] +proc-macro = true +[dependencies.proc-macro2] +version = "1.0" + +[dependencies.quote] +version = "1.0" + +[dependencies.syn] +version = "1.0" diff --git a/Cargo.toml.orig b/Cargo.toml.orig new file mode 100644 index 0000000..938bfe8 --- /dev/null +++ b/Cargo.toml.orig @@ -0,0 +1,21 @@ +[package] +name = "enumn" +version = "0.1.3" +authors = ["David Tolnay <dtolnay@gmail.com>"] +edition = "2018" +license = "MIT OR Apache-2.0" +description = "Convert number to enum" +repository = "https://github.com/dtolnay/enumn" +documentation = "https://docs.rs/enumn" +readme = "README.md" + +[lib] +proc-macro = true + +[dependencies] +proc-macro2 = "1.0" +quote = "1.0" +syn = "1.0" + +[package.metadata.docs.rs] +targets = ["x86_64-unknown-linux-gnu"] @@ -0,0 +1 @@ +LICENSE-APACHE
\ No newline at end of file diff --git a/LICENSE-APACHE b/LICENSE-APACHE new file mode 100644 index 0000000..16fe87b --- /dev/null +++ b/LICENSE-APACHE @@ -0,0 +1,201 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + +TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + +1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. For the purposes of this definition, + "control" means (i) the power, direct or indirect, to cause the + direction or management of such entity, whether by contract or + otherwise, or (ii) ownership of fifty percent (50%) or more of the + outstanding shares, or (iii) beneficial ownership of such entity. + + "You" (or "Your") shall mean an individual or Legal Entity + exercising permissions granted by this License. + + "Source" form shall mean the preferred form for making modifications, + including but not limited to software source code, documentation + source, and configuration files. + + "Object" form shall mean any form resulting from mechanical + transformation or translation of a Source form, including but + not limited to compiled object code, generated documentation, + and conversions to other media types. + + "Work" shall mean the work of authorship, whether in Source or + Object form, made available under the License, as indicated by a + copyright notice that is included in or attached to the work + (an example is provided in the Appendix below). + + "Derivative Works" shall mean any work, whether in Source or Object + form, that is based on (or derived from) the Work and for which the + editorial revisions, annotations, elaborations, or other modifications + represent, as a whole, an original work of authorship. For the purposes + of this License, Derivative Works shall not include works that remain + separable from, or merely link (or bind by name) to the interfaces of, + the Work and Derivative Works thereof. + + "Contribution" shall mean any work of authorship, including + the original version of the Work and any modifications or additions + to that Work or Derivative Works thereof, that is intentionally + submitted to Licensor for inclusion in the Work by the copyright owner + or by an individual or Legal Entity authorized to submit on behalf of + the copyright owner. For the purposes of this definition, "submitted" + means any form of electronic, verbal, or written communication sent + to the Licensor or its representatives, including but not limited to + communication on electronic mailing lists, source code control systems, + and issue tracking systems that are managed by, or on behalf of, the + Licensor for the purpose of discussing and improving the Work, but + excluding communication that is conspicuously marked or otherwise + designated in writing by the copyright owner as "Not a Contribution." + + "Contributor" shall mean Licensor and any individual or Legal Entity + on behalf of whom a Contribution has been received by Licensor and + subsequently incorporated within the Work. + +2. Grant of Copyright License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + copyright license to reproduce, prepare Derivative Works of, + publicly display, publicly perform, sublicense, and distribute the + Work and such Derivative Works in Source or Object form. + +3. Grant of Patent License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + (except as stated in this section) patent license to make, have made, + use, offer to sell, sell, import, and otherwise transfer the Work, + where such license applies only to those patent claims licensable + by such Contributor that are necessarily infringed by their + Contribution(s) alone or by combination of their Contribution(s) + with the Work to which such Contribution(s) was submitted. If You + institute patent litigation against any entity (including a + cross-claim or counterclaim in a lawsuit) alleging that the Work + or a Contribution incorporated within the Work constitutes direct + or contributory patent infringement, then any patent licenses + granted to You under this License for that Work shall terminate + as of the date such litigation is filed. + +4. Redistribution. You may reproduce and distribute copies of the + Work or Derivative Works thereof in any medium, with or without + modifications, and in Source or Object form, provided that You + meet the following conditions: + + (a) You must give any other recipients of the Work or + Derivative Works a copy of this License; and + + (b) You must cause any modified files to carry prominent notices + stating that You changed the files; and + + (c) You must retain, in the Source form of any Derivative Works + that You distribute, all copyright, patent, trademark, and + attribution notices from the Source form of the Work, + excluding those notices that do not pertain to any part of + the Derivative Works; and + + (d) If the Work includes a "NOTICE" text file as part of its + distribution, then any Derivative Works that You distribute must + include a readable copy of the attribution notices contained + within such NOTICE file, excluding those notices that do not + pertain to any part of the Derivative Works, in at least one + of the following places: within a NOTICE text file distributed + as part of the Derivative Works; within the Source form or + documentation, if provided along with the Derivative Works; or, + within a display generated by the Derivative Works, if and + wherever such third-party notices normally appear. The contents + of the NOTICE file are for informational purposes only and + do not modify the License. You may add Your own attribution + notices within Derivative Works that You distribute, alongside + or as an addendum to the NOTICE text from the Work, provided + that such additional attribution notices cannot be construed + as modifying the License. + + You may add Your own copyright statement to Your modifications and + may provide additional or different license terms and conditions + for use, reproduction, or distribution of Your modifications, or + for any such Derivative Works as a whole, provided Your use, + reproduction, and distribution of the Work otherwise complies with + the conditions stated in this License. + +5. Submission of Contributions. Unless You explicitly state otherwise, + any Contribution intentionally submitted for inclusion in the Work + by You to the Licensor shall be under the terms and conditions of + this License, without any additional terms or conditions. + Notwithstanding the above, nothing herein shall supersede or modify + the terms of any separate license agreement you may have executed + with Licensor regarding such Contributions. + +6. Trademarks. This License does not grant permission to use the trade + names, trademarks, service marks, or product names of the Licensor, + except as required for reasonable and customary use in describing the + origin of the Work and reproducing the content of the NOTICE file. + +7. Disclaimer of Warranty. Unless required by applicable law or + agreed to in writing, Licensor provides the Work (and each + Contributor provides its Contributions) on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied, including, without limitation, any warranties or conditions + of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A + PARTICULAR PURPOSE. You are solely responsible for determining the + appropriateness of using or redistributing the Work and assume any + risks associated with Your exercise of permissions under this License. + +8. Limitation of Liability. In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + +9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + +END OF TERMS AND CONDITIONS + +APPENDIX: How to apply the Apache License to your work. + + To apply the Apache License to your work, attach the following + boilerplate notice, with the fields enclosed by brackets "[]" + replaced with your own identifying information. (Don't include + the brackets!) The text should be enclosed in the appropriate + comment syntax for the file format. We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + +Copyright [yyyy] [name of copyright owner] + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. diff --git a/LICENSE-MIT b/LICENSE-MIT new file mode 100644 index 0000000..31aa793 --- /dev/null +++ b/LICENSE-MIT @@ -0,0 +1,23 @@ +Permission is hereby granted, free of charge, to any +person obtaining a copy of this software and associated +documentation files (the "Software"), to deal in the +Software without restriction, including without +limitation the rights to use, copy, modify, merge, +publish, distribute, sublicense, and/or sell copies of +the Software, and to permit persons to whom the Software +is furnished to do so, subject to the following +conditions: + +The above copyright notice and this permission notice +shall be included in all copies or substantial portions +of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF +ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED +TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A +PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT +SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR +IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. diff --git a/METADATA b/METADATA new file mode 100644 index 0000000..0cedc69 --- /dev/null +++ b/METADATA @@ -0,0 +1,20 @@ +name: "enumn" +description: "Convert number to enum" +third_party { + url { + type: HOMEPAGE + value: "https://crates.io/crates/enumn" + } + url { + type: ARCHIVE + value: "https://static.crates.io/crates/enumn/enumn-0.1.3.crate" + } + version: "0.1.3" + # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same. + license_type: NOTICE + last_upgrade_date { + year: 2021 + month: 12 + day: 2 + } +} diff --git a/MODULE_LICENSE_APACHE2 b/MODULE_LICENSE_APACHE2 new file mode 100644 index 0000000..e69de29 --- /dev/null +++ b/MODULE_LICENSE_APACHE2 @@ -0,0 +1 @@ +include platform/prebuilts/rust:master:/OWNERS diff --git a/README.md b/README.md new file mode 100644 index 0000000..d931a6a --- /dev/null +++ b/README.md @@ -0,0 +1,110 @@ +Convert number to enum +====================== + +[<img alt="github" src="https://img.shields.io/badge/github-dtolnay/enumn-8da0cb?style=for-the-badge&labelColor=555555&logo=github" height="20">](https://github.com/dtolnay/enumn) +[<img alt="crates.io" src="https://img.shields.io/crates/v/enumn.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/enumn) +[<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-enumn-66c2a5?style=for-the-badge&labelColor=555555&logoColor=white&logo=data:image/svg+xml;base64,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" height="20">](https://docs.rs/enumn) +[<img alt="build status" src="https://img.shields.io/github/workflow/status/dtolnay/enumn/CI/master?style=for-the-badge" height="20">](https://github.com/dtolnay/enumn/actions?query=branch%3Amaster) + +This crate provides a derive macro to generate a function for converting a +primitive integer into the corresponding variant of an enum. + +The generated function is named `n` and has the following signature: + +```rust +impl YourEnum { + pub fn n(value: Repr) -> Option<Self>; +} +``` + +where `Repr` is an integer type of the right size as described in more +detail below. + +## Example + +```rust +use enumn::N; + +#[derive(PartialEq, Debug, N)] +enum Status { + LegendaryTriumph, + QualifiedSuccess, + FortuitousRevival, + IndeterminateStalemate, + RecoverableSetback, + DireMisadventure, + AbjectFailure, +} + +fn main() { + let s = Status::n(1); + assert_eq!(s, Some(Status::QualifiedSuccess)); + + let s = Status::n(9); + assert_eq!(s, None); +} +``` + +## Signature + +The generated signature depends on whether the enum has a `#[repr(..)]` +attribute. If a `repr` is specified, the input to `n` will be required to be +of that type. + +```rust +#[derive(enumn::N)] +#[repr(u8)] +enum E { + /* ... */ +} + +// expands to: +impl E { + pub fn n(value: u8) -> Option<Self> { + /* ... */ + } +} +``` + +On the other hand if no `repr` is specified then we get a signature that is +generic over a variety of possible types. + +```rust +impl E { + pub fn n<REPR: Into<i64>>(value: REPR) -> Option<Self> { + /* ... */ + } +} +``` + +## Discriminants + +The conversion respects explictly specified enum discriminants. Consider +this enum: + +```rust +#[derive(enumn::N)] +enum Letter { + A = 65, + B = 66, +} +``` + +Here `Letter::n(65)` would return `Some(Letter::A)`. + +<br> + +#### License + +<sup> +Licensed under either of <a href="LICENSE-APACHE">Apache License, Version +2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option. +</sup> + +<br> + +<sub> +Unless you explicitly state otherwise, any contribution intentionally submitted +for inclusion in this crate by you, as defined in the Apache-2.0 license, shall +be dual licensed as above, without any additional terms or conditions. +</sub> diff --git a/cargo2android.json b/cargo2android.json new file mode 100644 index 0000000..5c18d15 --- /dev/null +++ b/cargo2android.json @@ -0,0 +1,9 @@ +{ + "apex-available": [ + "//apex_available:platform", + "com.android.virt" + ], + "dependencies": true, + "device": true, + "run": true +} diff --git a/src/lib.rs b/src/lib.rs new file mode 100644 index 0000000..9639ee2 --- /dev/null +++ b/src/lib.rs @@ -0,0 +1,199 @@ +//! [![github]](https://github.com/dtolnay/enumn) [![crates-io]](https://crates.io/crates/enumn) [![docs-rs]](https://docs.rs/enumn) +//! +//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github +//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust +//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logoColor=white&logo=data:image/svg+xml;base64,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 +//! +//! <br> +//! +//! Convert number to enum. +//! +//! This crate provides a derive macro to generate a function for converting a +//! primitive integer into the corresponding variant of an enum. +//! +//! The generated function is named `n` and has the following signature: +//! +//! ``` +//! # const IGNORE: &str = stringify! { +//! impl YourEnum { +//! pub fn n(value: Repr) -> Option<Self>; +//! } +//! # }; +//! ``` +//! +//! where `Repr` is an integer type of the right size as described in more +//! detail below. +//! +//! # Example +//! +//! ``` +//! use enumn::N; +//! +//! #[derive(PartialEq, Debug, N)] +//! enum Status { +//! LegendaryTriumph, +//! QualifiedSuccess, +//! FortuitousRevival, +//! IndeterminateStalemate, +//! RecoverableSetback, +//! DireMisadventure, +//! AbjectFailure, +//! } +//! +//! fn main() { +//! let s = Status::n(1); +//! assert_eq!(s, Some(Status::QualifiedSuccess)); +//! +//! let s = Status::n(9); +//! assert_eq!(s, None); +//! } +//! ``` +//! +//! # Signature +//! +//! The generated signature depends on whether the enum has a `#[repr(..)]` +//! attribute. If a `repr` is specified, the input to `n` will be required to be +//! of that type. +//! +//! ``` +//! #[derive(enumn::N)] +//! # enum E0 { +//! # IGNORE +//! # } +//! # +//! #[repr(u8)] +//! enum E { +//! /* ... */ +//! # IGNORE +//! } +//! +//! // expands to: +//! impl E { +//! pub fn n(value: u8) -> Option<Self> { +//! /* ... */ +//! # unimplemented!() +//! } +//! } +//! ``` +//! +//! On the other hand if no `repr` is specified then we get a signature that is +//! generic over a variety of possible types. +//! +//! ``` +//! # enum E {} +//! # +//! impl E { +//! pub fn n<REPR: Into<i64>>(value: REPR) -> Option<Self> { +//! /* ... */ +//! # unimplemented!() +//! } +//! } +//! ``` +//! +//! # Discriminants +//! +//! The conversion respects explictly specified enum discriminants. Consider +//! this enum: +//! +//! ``` +//! #[derive(enumn::N)] +//! enum Letter { +//! A = 65, +//! B = 66, +//! } +//! ``` +//! +//! Here `Letter::n(65)` would return `Some(Letter::A)`. + +extern crate proc_macro; + +use proc_macro::TokenStream; +use quote::quote; +use syn::{parse_macro_input, Data, DeriveInput, Error, Fields, Ident}; + +#[proc_macro_derive(N)] +pub fn derive(input: TokenStream) -> TokenStream { + let input = parse_macro_input!(input as DeriveInput); + + let variants = match input.data { + Data::Enum(data) => data.variants, + Data::Struct(_) | Data::Union(_) => panic!("input must be an enum"), + }; + + for variant in &variants { + match variant.fields { + Fields::Unit => {} + Fields::Named(_) | Fields::Unnamed(_) => { + let span = variant.ident.span(); + let err = Error::new(span, "enumn: variant with data is not supported"); + return err.to_compile_error().into(); + } + } + } + + // Parse repr attribute like #[repr(u16)]. + let mut repr = None; + for attr in input.attrs { + if attr.path.is_ident("repr") { + if let Ok(name) = attr.parse_args::<Ident>() { + match name.to_string().as_str() { + "u8" | "u16" | "u32" | "u64" | "u128" | "usize" | "i8" | "i16" | "i32" + | "i64" | "i128" | "isize" => { + repr = Some(quote!(#name)); + } + _ => {} + } + } + } + } + + let signature; + let value; + match repr { + Some(ref repr) => { + signature = quote! { + fn n(value: #repr) + }; + value = quote!(value); + } + None => { + repr = Some(quote!(i64)); + signature = quote! { + fn n<REPR: Into<i64>>(value: REPR) + }; + value = quote! { + <REPR as Into<i64>>::into(value) + }; + } + } + + let ident = input.ident; + let declare_discriminants = variants.iter().map(|variant| { + let variant = &variant.ident; + quote! { + const #variant: #repr = #ident::#variant as #repr; + } + }); + let match_discriminants = variants.iter().map(|variant| { + let variant = &variant.ident; + quote! { + discriminant::#variant => Some(#ident::#variant), + } + }); + + TokenStream::from(quote! { + impl #ident { + pub #signature -> Option<Self> { + struct discriminant; + #[allow(non_upper_case_globals)] + impl discriminant { + #(#declare_discriminants)* + } + match #value { + #(#match_discriminants)* + _ => None, + } + } + } + }) +} |