Merge remote-tracking branch 'origin/upstream' am: 65408a8cd5 am: b32946e303
Original change: undetermined
Change-Id: Iecf15fa797c3dc8fef88a4f4c749c576bcf215f6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
new file mode 100644
index 0000000..de41e72
--- /dev/null
+++ b/.cargo_vcs_info.json
@@ -0,0 +1,6 @@
+{
+ "git": {
+ "sha1": "f0b62a55ec2495b1a60b18f1d93f8b27e53123a7"
+ },
+ "path_in_vcs": ""
+}
\ No newline at end of file
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..7bf4d5e
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,120 @@
+on:
+ push:
+ pull_request:
+ schedule:
+ - cron: '0 0 * * *'
+
+name: Continuous integration
+
+jobs:
+ check:
+ name: Check
+ runs-on: ubuntu-latest
+ strategy:
+ matrix:
+ rust:
+ - stable
+ - 1.56.0
+ steps:
+ - uses: actions/checkout@v1
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: ${{ matrix.rust }}
+ override: true
+ - uses: actions-rs/cargo@v1
+ with:
+ command: check
+
+ test:
+ name: Test Suite
+ runs-on: ubuntu-latest
+ strategy:
+ matrix:
+ rust:
+ - stable
+ - nightly
+ steps:
+ - uses: actions/checkout@v1
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: ${{ matrix.rust }}
+ override: true
+ - uses: Swatinem/rust-cache@v1
+ - name: Install cargo-nextest
+ uses: baptiste0928/cargo-install@v1
+ with:
+ crate: cargo-nextest
+ version: 0.9
+ - uses: actions-rs/cargo@v1
+ with:
+ command: nextest
+ args: run
+ - uses: actions-rs/cargo@v1
+ with:
+ command: nextest
+ args: run --no-default-features
+ - uses: actions-rs/cargo@v1
+ with:
+ command: test
+ args: --doc
+
+ test-msrv:
+ name: msrv Test Suite
+ runs-on: ubuntu-latest
+ strategy:
+ matrix:
+ rust:
+ - 1.56.0
+ steps:
+ - uses: actions/checkout@v1
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: ${{ matrix.rust }}
+ override: true
+ - uses: Swatinem/rust-cache@v1
+ - uses: actions-rs/cargo@v1
+ with:
+ command: test
+ - uses: actions-rs/cargo@v1
+ with:
+ command: test
+ args: --no-default-features
+
+ fmt:
+ name: Rustfmt
+ runs-on: ubuntu-latest
+ strategy:
+ matrix:
+ rust:
+ - stable
+ - 1.56.0
+ steps:
+ - uses: actions/checkout@v1
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: ${{ matrix.rust }}
+ override: true
+ - run: rustup component add rustfmt
+ - uses: actions-rs/cargo@v1
+ with:
+ command: fmt
+ args: --all -- --check
+
+ clippy:
+ name: Clippy
+ runs-on: ubuntu-latest
+ strategy:
+ matrix:
+ rust:
+ - stable
+ steps:
+ - uses: actions/checkout@v1
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: ${{ matrix.rust }}
+ override: true
+ - run: rustup component add clippy
+ - uses: actions-rs/cargo@v1
+ with:
+ command: clippy
+ args: -- -D warnings
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2411493
--- /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..e4c7c8a
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,23 @@
+// This file is generated by cargo_embargo.
+// Do not modify this file as changes will be overridden on upgrade.
+
+// TODO: Add license.
+rust_proc_macro {
+ name: "libdisplaydoc",
+ crate_name: "displaydoc",
+ cargo_env_compat: true,
+ cargo_pkg_version: "0.2.4",
+ srcs: ["src/lib.rs"],
+ edition: "2018",
+ features: [
+ "default",
+ "std",
+ ],
+ rustlibs: [
+ "libproc_macro2",
+ "libquote",
+ "libsyn",
+ ],
+ product_available: true,
+ vendor_available: true,
+}
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..4513b4a
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,50 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+<!-- next-header -->
+
+## [Unreleased] - ReleaseDate
+
+# [0.2.4] - 2022-05-02
+
+## Added
+- Updated `syn` dependency to 2.0
+- Support for empty enums
+- Implicitly require fmt::Display on all type parameters unless overridden
+
+## Changed
+- Bumped MSRV to 1.56
+
+# [0.2.3] - 2021-07-16
+## Added
+- Added `#[displaydoc("..")]` attribute for overriding a doc comment
+
+# [0.2.2] - 2021-07-01
+## Added
+- Added prefix feature to use the doc comment from an enum and prepend it
+ before the error message from each variant.
+
+# [0.2.1] - 2021-03-26
+## Added
+- Added opt in support for ignoring extra doc attributes
+
+# [0.2.0] - 2021-03-16
+## Changed
+
+- (BREAKING) disallow multiple `doc` attributes in display impl
+ [https://github.com/yaahc/displaydoc/pull/22]. Allowing and ignoring extra
+ doc attributes made it too easy to accidentally create a broken display
+ implementation with missing context without realizing it, this change turns
+ that into a hard error and directs users towards block comments if multiple
+ lines are needed.
+
+<!-- next-url -->
+[Unreleased]: https://github.com/yaahc/displaydoc/compare/v0.2.4...HEAD
+[0.2.4]: https://github.com/yaahc/displaydoc/compare/v0.2.3...v0.2.4
+[0.2.3]: https://github.com/yaahc/displaydoc/compare/v0.2.2...v0.2.3
+[0.2.2]: https://github.com/yaahc/displaydoc/compare/v0.2.1...v0.2.2
+[0.2.1]: https://github.com/yaahc/displaydoc/compare/v0.2.0...v0.2.1
+[0.2.0]: https://github.com/yaahc/displaydoc/releases/tag/v0.2.0
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..1affcca
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,114 @@
+# 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 are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "displaydoc"
+version = "0.2.4"
+authors = ["Jane Lusby <jlusby@yaah.dev>"]
+description = """
+A derive macro for implementing the display Trait via a doc comment and string interpolation
+"""
+homepage = "https://github.com/yaahc/displaydoc"
+documentation = "https://docs.rs/displaydoc"
+readme = "README.md"
+keywords = [
+ "display",
+ "derive",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/yaahc/displaydoc"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = [
+ "--cfg",
+ "docsrs",
+]
+
+[package.metadata.release]
+no-dev-version = true
+pre-release-hook = ["./update-readme.sh"]
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "Unreleased"
+replace = "{{version}}"
+
+[[package.metadata.release.pre-release-replacements]]
+file = "src/lib.rs"
+search = '#!\[doc\(html_root_url.*'
+replace = "#![doc(html_root_url = \"https://docs.rs/{{crate_name}}/{{version}}\")]"
+exactly = 1
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "ReleaseDate"
+replace = "{{date}}"
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "<!-- next-header -->"
+replace = """
+<!-- next-header -->
+
+# [Unreleased] - ReleaseDate"""
+exactly = 1
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = '\.\.\.HEAD'
+replace = "...{{tag_name}}"
+exactly = 1
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "<!-- next-url -->"
+replace = """
+<!-- next-url -->
+[Unreleased]: https://github.com/yaahc/{{crate_name}}/compare/{{tag_name}}...HEAD"""
+exactly = 1
+
+[lib]
+path = "src/lib.rs"
+proc-macro = true
+
+[dependencies.proc-macro2]
+version = "1.0"
+
+[dependencies.quote]
+version = "1.0"
+
+[dependencies.syn]
+version = "2.0"
+
+[dev-dependencies.libc]
+version = "0.2"
+default-features = false
+
+[dev-dependencies.pretty_assertions]
+version = "0.6.1"
+
+[dev-dependencies.rustversion]
+version = "1.0.0"
+
+[dev-dependencies.static_assertions]
+version = "1.1"
+
+[dev-dependencies.thiserror]
+version = "1.0.24"
+
+[dev-dependencies.trybuild]
+version = "1.0"
+
+[features]
+default = ["std"]
+std = []
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
new file mode 100644
index 0000000..5528713
--- /dev/null
+++ b/Cargo.toml.orig
@@ -0,0 +1,80 @@
+[package]
+name = "displaydoc"
+version = "0.2.4"
+authors = ["Jane Lusby <jlusby@yaah.dev>"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+repository = "https://github.com/yaahc/displaydoc"
+homepage = "https://github.com/yaahc/displaydoc"
+documentation = "https://docs.rs/displaydoc"
+keywords = ["display", "derive"]
+description = """
+A derive macro for implementing the display Trait via a doc comment and string interpolation
+"""
+
+[lib]
+proc-macro = true
+path = "src/lib.rs"
+
+[features]
+default = ["std"]
+std = []
+
+[dependencies]
+syn = "2.0"
+quote = "1.0"
+proc-macro2 = "1.0"
+
+[dev-dependencies]
+trybuild = "1.0"
+static_assertions = "1.1"
+libc = { version = "0.2", default-features = false }
+rustversion = "1.0.0"
+pretty_assertions = "0.6.1"
+thiserror = "1.0.24"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[package.metadata.release]
+no-dev-version = true
+pre-release-hook = ["./update-readme.sh"]
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "Unreleased"
+replace="{{version}}"
+
+[[package.metadata.release.pre-release-replacements]]
+file = "src/lib.rs"
+search = "#!\\[doc\\(html_root_url.*"
+replace = "#![doc(html_root_url = \"https://docs.rs/{{crate_name}}/{{version}}\")]"
+exactly = 1
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "ReleaseDate"
+replace="{{date}}"
+
+[[package.metadata.release.pre-release-replacements]]
+file="CHANGELOG.md"
+search="<!-- next-header -->"
+replace="<!-- next-header -->\n\n# [Unreleased] - ReleaseDate"
+exactly=1
+
+# Disable this replacement on the very first release
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = "\\.\\.\\.HEAD"
+replace="...{{tag_name}}"
+exactly = 1
+# END SECTION, do not comment out the replacement below this, and do not reorder them
+
+[[package.metadata.release.pre-release-replacements]]
+file="CHANGELOG.md"
+search="<!-- next-url -->"
+replace="<!-- next-url -->\n[Unreleased]: https://github.com/yaahc/{{crate_name}}/compare/{{tag_name}}...HEAD"
+exactly=1
+
diff --git a/LICENSE b/LICENSE
new file mode 120000
index 0000000..6b579aa
--- /dev/null
+++ b/LICENSE
@@ -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..f47c941
--- /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.
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+ "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
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+ 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
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+ 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.
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+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
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+ 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
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+ 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
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+
+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..458723b
--- /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..7fda2bb
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,20 @@
+name: "displaydoc"
+description: "()"
+third_party {
+ identifier {
+ type: "crates.io"
+ value: "https://crates.io/crates/displaydoc"
+ }
+ identifier {
+ type: "Archive"
+ value: "https://static.crates.io/crates/displaydoc/displaydoc-0.2.4.crate"
+ }
+ version: "0.2.4"
+ # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same.
+ license_type: NOTICE
+ last_upgrade_date {
+ year: 2023
+ month: 11
+ day: 21
+ }
+}
diff --git a/MODULE_LICENSE_APACHE2 b/MODULE_LICENSE_APACHE2
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/MODULE_LICENSE_APACHE2
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..5a2b844
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1 @@
+include platform/prebuilts/rust:main:/OWNERS
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b8fa091
--- /dev/null
+++ b/README.md
@@ -0,0 +1,115 @@
+derive(Display) /// `From<docs>`
+===============
+
+[](https://crates.io/crates/displaydoc)
+[](https://docs.rs/displaydoc)
+
+This library provides a convenient derive macro for the standard library's
+[`core::fmt::Display`] trait.
+
+[`core::fmt::Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html
+
+```toml
+[dependencies]
+displaydoc = "0.2"
+```
+
+*Compiler support: requires rustc 1.56+*
+
+<br>
+
+### Example
+
+*Demonstration alongside the [`Error`][std::error::Error] derive macro from [`thiserror`](https://docs.rs/thiserror/1.0.25/thiserror/index.html),
+to propagate source locations from [`io::Error`][std::io::Error] with the `#[source]` attribute:*
+```rust
+use std::io;
+use displaydoc::Display;
+use thiserror::Error;
+
+#[derive(Display, Error, Debug)]
+pub enum DataStoreError {
+ /// data store disconnected
+ Disconnect(#[source] io::Error),
+ /// the data for key `{0}` is not available
+ Redaction(String),
+ /// invalid header (expected {expected:?}, found {found:?})
+ InvalidHeader {
+ expected: String,
+ found: String,
+ },
+ /// unknown data store error
+ Unknown,
+}
+
+let error = DataStoreError::Redaction("CLASSIFIED CONTENT".to_string());
+assert!("the data for key `CLASSIFIED CONTENT` is not available" == &format!("{}", error));
+```
+*Note that although [`io::Error`][std::io::Error] implements `Display`, we do not add it to the
+generated message for `DataStoreError::Disconnect`, since it is already made available via
+`#[source]`. See further context on avoiding duplication in error reports at the rust blog
+[here](https://github.com/yaahc/blog.rust-lang.org/blob/master/posts/inside-rust/2021-05-15-What-the-error-handling-project-group-is-working-towards.md#duplicate-information-issue).*
+
+<br>
+
+### Details
+
+- A `fmt::Display` impl is generated for your enum if you provide
+ a docstring comment on each variant as shown above in the example. The
+ `Display` derive macro supports a shorthand for interpolating fields from
+ the error:
+ - `/// {var}` ⟶ `write!("{}", self.var)`
+ - `/// {0}` ⟶ `write!("{}", self.0)`
+ - `/// {var:?}` ⟶ `write!("{:?}", self.var)`
+ - `/// {0:?}` ⟶ `write!("{:?}", self.0)`
+- This also works with structs and [generic types][crate::Display#generic-type-parameters]:
+```rust
+/// oh no, an error: {0}
+#[derive(Display)]
+pub struct Error<E>(pub E);
+
+let error: Error<&str> = Error("muahaha i am an error");
+assert!("oh no, an error: muahaha i am an error" == &format!("{}", error));
+```
+
+- Two optional attributes can be added to your types next to the derive:
+
+ - `#[ignore_extra_doc_attributes]` makes the macro ignore any doc
+ comment attributes (or `///` lines) after the first. Multi-line
+ comments using `///` are otherwise treated as an error, so use this
+ attribute or consider switching to block doc comments (`/** */`).
+
+ - `#[prefix_enum_doc_attributes]` combines the doc comment message on
+ your enum itself with the messages for each variant, in the format
+ “enum: variant”. When added to an enum, the doc comment on the enum
+ becomes mandatory. When added to any other type, it has no effect.
+
+- In case you want to have an independent doc comment, the
+ `#[displaydoc("...")` atrribute may be used on the variant or struct to
+ override it.
+
+<br>
+
+### FAQ
+
+1. **Is this crate `no_std` compatible?**
+ * Yes! This crate implements the [`core::fmt::Display`] trait, not the [`std::fmt::Display`] trait, so it should work in `std` and `no_std` environments. Just add `default-features = false`.
+
+2. **Does this crate work with `Path` and `PathBuf` via the `Display` trait?**
+ * Yuuup. This crate uses @dtolnay's [autoref specialization technique](https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md) to add a special trait for types to get the display impl. It then specializes for `Path` and `PathBuf`, and when either of these types are found, it calls `self.display()` to get a `std::path::Display<'_>` type which can be used with the `Display` format specifier!
+
+
+#### 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/README.tpl b/README.tpl
new file mode 100644
index 0000000..b131fb8
--- /dev/null
+++ b/README.tpl
@@ -0,0 +1,23 @@
+derive(Display) /// `From<docs>`
+===============
+
+[](https://crates.io/crates/displaydoc)
+[](https://docs.rs/displaydoc)
+
+{{readme}}
+
+
+#### 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/cargo_embargo.json b/cargo_embargo.json
new file mode 100644
index 0000000..fca634f
--- /dev/null
+++ b/cargo_embargo.json
@@ -0,0 +1,3 @@
+{
+ "run_cargo": false
+}
diff --git a/examples/simple.rs b/examples/simple.rs
new file mode 100644
index 0000000..1f9fd11
--- /dev/null
+++ b/examples/simple.rs
@@ -0,0 +1,36 @@
+use displaydoc::Display;
+
+#[derive(Debug, Display)]
+pub enum DataStoreError {
+ /// data store disconnected
+ Disconnect,
+ /// the data for key `{0}` is not available
+ Redaction(String),
+ /// invalid header (expected {expected:?}, found {found:?})
+ InvalidHeader { expected: String, found: String },
+ /// unknown data store error
+ Unknown,
+}
+
+fn main() {
+ let disconnect = DataStoreError::Disconnect;
+ println!(
+ "Enum value `Disconnect` should be printed as:\n\t{}",
+ disconnect
+ );
+
+ let redaction = DataStoreError::Redaction(String::from("Dummy"));
+ println!(
+ "Enum value `Redaction` should be printed as:\n\t{}",
+ redaction
+ );
+
+ let invalid_header = DataStoreError::InvalidHeader {
+ expected: String::from("https"),
+ found: String::from("http"),
+ };
+ println!(
+ "Enum value `InvalidHeader` should be printed as:\n\t{}",
+ invalid_header
+ );
+}
diff --git a/src/attr.rs b/src/attr.rs
new file mode 100644
index 0000000..a965d04
--- /dev/null
+++ b/src/attr.rs
@@ -0,0 +1,137 @@
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{Attribute, LitStr, Meta, Result};
+
+#[derive(Clone)]
+pub(crate) struct Display {
+ pub(crate) fmt: LitStr,
+ pub(crate) args: TokenStream,
+}
+
+pub(crate) struct VariantDisplay {
+ pub(crate) r#enum: Option<Display>,
+ pub(crate) variant: Display,
+}
+
+impl ToTokens for Display {
+ fn to_tokens(&self, tokens: &mut TokenStream) {
+ let fmt = &self.fmt;
+ let args = &self.args;
+ tokens.extend(quote! {
+ write!(formatter, #fmt #args)
+ });
+ }
+}
+
+impl ToTokens for VariantDisplay {
+ fn to_tokens(&self, tokens: &mut TokenStream) {
+ if let Some(ref r#enum) = self.r#enum {
+ r#enum.to_tokens(tokens);
+ tokens.extend(quote! { ?; write!(formatter, ": ")?; });
+ }
+ self.variant.to_tokens(tokens);
+ }
+}
+
+pub(crate) struct AttrsHelper {
+ ignore_extra_doc_attributes: bool,
+ prefix_enum_doc_attributes: bool,
+}
+
+impl AttrsHelper {
+ pub(crate) fn new(attrs: &[Attribute]) -> Self {
+ let ignore_extra_doc_attributes = attrs
+ .iter()
+ .any(|attr| attr.path().is_ident("ignore_extra_doc_attributes"));
+ let prefix_enum_doc_attributes = attrs
+ .iter()
+ .any(|attr| attr.path().is_ident("prefix_enum_doc_attributes"));
+
+ Self {
+ ignore_extra_doc_attributes,
+ prefix_enum_doc_attributes,
+ }
+ }
+
+ pub(crate) fn display(&self, attrs: &[Attribute]) -> Result<Option<Display>> {
+ let displaydoc_attr = attrs.iter().find(|attr| attr.path().is_ident("displaydoc"));
+
+ if let Some(displaydoc_attr) = displaydoc_attr {
+ let lit = displaydoc_attr
+ .parse_args()
+ .expect("#[displaydoc(\"foo\")] must contain string arguments");
+ let mut display = Display {
+ fmt: lit,
+ args: TokenStream::new(),
+ };
+
+ display.expand_shorthand();
+ return Ok(Some(display));
+ }
+
+ let num_doc_attrs = attrs
+ .iter()
+ .filter(|attr| attr.path().is_ident("doc"))
+ .count();
+
+ if !self.ignore_extra_doc_attributes && num_doc_attrs > 1 {
+ panic!("Multi-line comments are disabled by default by displaydoc. Please consider using block doc comments (/** */) or adding the #[ignore_extra_doc_attributes] attribute to your type next to the derive.");
+ }
+
+ for attr in attrs {
+ if attr.path().is_ident("doc") {
+ let lit = match &attr.meta {
+ Meta::NameValue(syn::MetaNameValue {
+ value:
+ syn::Expr::Lit(syn::ExprLit {
+ lit: syn::Lit::Str(lit),
+ ..
+ }),
+ ..
+ }) => lit,
+ _ => unimplemented!(),
+ };
+
+ // Make an attempt at cleaning up multiline doc comments.
+ let doc_str = lit
+ .value()
+ .lines()
+ .map(|line| line.trim().trim_start_matches('*').trim())
+ .collect::<Vec<&str>>()
+ .join("\n");
+
+ let lit = LitStr::new(doc_str.trim(), lit.span());
+
+ let mut display = Display {
+ fmt: lit,
+ args: TokenStream::new(),
+ };
+
+ display.expand_shorthand();
+ return Ok(Some(display));
+ }
+ }
+
+ Ok(None)
+ }
+
+ pub(crate) fn display_with_input(
+ &self,
+ r#enum: &[Attribute],
+ variant: &[Attribute],
+ ) -> Result<Option<VariantDisplay>> {
+ let r#enum = if self.prefix_enum_doc_attributes {
+ let result = self
+ .display(r#enum)?
+ .expect("Missing doc comment on enum with #[prefix_enum_doc_attributes]. Please remove the attribute or add a doc comment to the enum itself.");
+
+ Some(result)
+ } else {
+ None
+ };
+
+ Ok(self
+ .display(variant)?
+ .map(|variant| VariantDisplay { r#enum, variant }))
+ }
+}
diff --git a/src/expand.rs b/src/expand.rs
new file mode 100644
index 0000000..8a84390
--- /dev/null
+++ b/src/expand.rs
@@ -0,0 +1,410 @@
+use super::attr::AttrsHelper;
+use proc_macro2::{Span, TokenStream};
+use quote::{format_ident, quote};
+use syn::{
+ punctuated::Punctuated,
+ token::{Colon, Comma, PathSep, Plus, Where},
+ Data, DataEnum, DataStruct, DeriveInput, Error, Fields, Generics, Ident, Path, PathArguments,
+ PathSegment, PredicateType, Result, TraitBound, TraitBoundModifier, Type, TypeParam,
+ TypeParamBound, TypePath, WhereClause, WherePredicate,
+};
+
+use std::collections::HashMap;
+
+pub(crate) fn derive(input: &DeriveInput) -> Result<TokenStream> {
+ let impls = match &input.data {
+ Data::Struct(data) => impl_struct(input, data),
+ Data::Enum(data) => impl_enum(input, data),
+ Data::Union(_) => Err(Error::new_spanned(input, "Unions are not supported")),
+ }?;
+
+ let helpers = specialization();
+ let dummy_const = format_ident!("_DERIVE_Display_FOR_{}", input.ident);
+ Ok(quote! {
+ #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+ const #dummy_const: () = {
+ #helpers
+ #impls
+ };
+ })
+}
+
+#[cfg(feature = "std")]
+fn specialization() -> TokenStream {
+ quote! {
+ trait DisplayToDisplayDoc {
+ fn __displaydoc_display(&self) -> Self;
+ }
+
+ impl<T: core::fmt::Display> DisplayToDisplayDoc for &T {
+ fn __displaydoc_display(&self) -> Self {
+ self
+ }
+ }
+
+ // If the `std` feature gets enabled we want to ensure that any crate
+ // using displaydoc can still reference the std crate, which is already
+ // being compiled in by whoever enabled the `std` feature in
+ // `displaydoc`, even if the crates using displaydoc are no_std.
+ extern crate std;
+
+ trait PathToDisplayDoc {
+ fn __displaydoc_display(&self) -> std::path::Display<'_>;
+ }
+
+ impl PathToDisplayDoc for std::path::Path {
+ fn __displaydoc_display(&self) -> std::path::Display<'_> {
+ self.display()
+ }
+ }
+
+ impl PathToDisplayDoc for std::path::PathBuf {
+ fn __displaydoc_display(&self) -> std::path::Display<'_> {
+ self.display()
+ }
+ }
+ }
+}
+
+#[cfg(not(feature = "std"))]
+fn specialization() -> TokenStream {
+ quote! {}
+}
+
+fn impl_struct(input: &DeriveInput, data: &DataStruct) -> Result<TokenStream> {
+ let ty = &input.ident;
+ let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+ let where_clause = generate_where_clause(&input.generics, where_clause);
+
+ let helper = AttrsHelper::new(&input.attrs);
+
+ let display = helper.display(&input.attrs)?.map(|display| {
+ let pat = match &data.fields {
+ Fields::Named(fields) => {
+ let var = fields.named.iter().map(|field| &field.ident);
+ quote!(Self { #(#var),* })
+ }
+ Fields::Unnamed(fields) => {
+ let var = (0..fields.unnamed.len()).map(|i| format_ident!("_{}", i));
+ quote!(Self(#(#var),*))
+ }
+ Fields::Unit => quote!(_),
+ };
+ quote! {
+ impl #impl_generics core::fmt::Display for #ty #ty_generics #where_clause {
+ fn fmt(&self, formatter: &mut core::fmt::Formatter) -> core::fmt::Result {
+ // NB: This destructures the fields of `self` into named variables (for unnamed
+ // fields, it uses _0, _1, etc as above). The `#[allow(unused_variables)]`
+ // section means it doesn't have to parse the individual field references out of
+ // the docstring.
+ #[allow(unused_variables)]
+ let #pat = self;
+ #display
+ }
+ }
+ }
+ });
+
+ Ok(quote! { #display })
+}
+
+/// Create a `where` predicate for `ident`, without any [bound][TypeParamBound]s yet.
+fn new_empty_where_type_predicate(ident: Ident) -> PredicateType {
+ let mut path_segments = Punctuated::<PathSegment, PathSep>::new();
+ path_segments.push_value(PathSegment {
+ ident,
+ arguments: PathArguments::None,
+ });
+ PredicateType {
+ lifetimes: None,
+ bounded_ty: Type::Path(TypePath {
+ qself: None,
+ path: Path {
+ leading_colon: None,
+ segments: path_segments,
+ },
+ }),
+ colon_token: Colon {
+ spans: [Span::call_site()],
+ },
+ bounds: Punctuated::<TypeParamBound, Plus>::new(),
+ }
+}
+
+/// Create a `where` clause that we can add [WherePredicate]s to.
+fn new_empty_where_clause() -> WhereClause {
+ WhereClause {
+ where_token: Where {
+ span: Span::call_site(),
+ },
+ predicates: Punctuated::<WherePredicate, Comma>::new(),
+ }
+}
+
+enum UseGlobalPrefix {
+ LeadingColon,
+ #[allow(dead_code)]
+ NoLeadingColon,
+}
+
+/// Create a path with segments composed of [Idents] *without* any [PathArguments].
+fn join_paths(name_segments: &[&str], use_global_prefix: UseGlobalPrefix) -> Path {
+ let mut segments = Punctuated::<PathSegment, PathSep>::new();
+ assert!(!name_segments.is_empty());
+ segments.push_value(PathSegment {
+ ident: Ident::new(name_segments[0], Span::call_site()),
+ arguments: PathArguments::None,
+ });
+ for name in name_segments[1..].iter() {
+ segments.push_punct(PathSep {
+ spans: [Span::call_site(), Span::mixed_site()],
+ });
+ segments.push_value(PathSegment {
+ ident: Ident::new(name, Span::call_site()),
+ arguments: PathArguments::None,
+ });
+ }
+ Path {
+ leading_colon: match use_global_prefix {
+ UseGlobalPrefix::LeadingColon => Some(PathSep {
+ spans: [Span::call_site(), Span::mixed_site()],
+ }),
+ UseGlobalPrefix::NoLeadingColon => None,
+ },
+ segments,
+ }
+}
+
+/// Push `new_type_predicate` onto the end of `where_clause`.
+fn append_where_clause_type_predicate(
+ where_clause: &mut WhereClause,
+ new_type_predicate: PredicateType,
+) {
+ // Push a comma at the end if there are already any `where` predicates.
+ if !where_clause.predicates.is_empty() {
+ where_clause.predicates.push_punct(Comma {
+ spans: [Span::call_site()],
+ });
+ }
+ where_clause
+ .predicates
+ .push_value(WherePredicate::Type(new_type_predicate));
+}
+
+/// Add a requirement for [core::fmt::Display] to a `where` predicate for some type.
+fn add_display_constraint_to_type_predicate(
+ predicate_that_needs_a_display_impl: &mut PredicateType,
+) {
+ // Create a `Path` of `::core::fmt::Display`.
+ let display_path = join_paths(&["core", "fmt", "Display"], UseGlobalPrefix::LeadingColon);
+
+ let display_bound = TypeParamBound::Trait(TraitBound {
+ paren_token: None,
+ modifier: TraitBoundModifier::None,
+ lifetimes: None,
+ path: display_path,
+ });
+ if !predicate_that_needs_a_display_impl.bounds.is_empty() {
+ predicate_that_needs_a_display_impl.bounds.push_punct(Plus {
+ spans: [Span::call_site()],
+ });
+ }
+
+ predicate_that_needs_a_display_impl
+ .bounds
+ .push_value(display_bound);
+}
+
+/// Map each declared generic type parameter to the set of all trait boundaries declared on it.
+///
+/// These boundaries may come from the declaration site:
+/// pub enum E<T: MyTrait> { ... }
+/// or a `where` clause after the parameter declarations:
+/// pub enum E<T> where T: MyTrait { ... }
+/// This method will return the boundaries from both of those cases.
+fn extract_trait_constraints_from_source(
+ where_clause: &WhereClause,
+ type_params: &[&TypeParam],
+) -> HashMap<Ident, Vec<TraitBound>> {
+ // Add trait bounds provided at the declaration site of type parameters for the struct/enum.
+ let mut param_constraint_mapping: HashMap<Ident, Vec<TraitBound>> = type_params
+ .iter()
+ .map(|type_param| {
+ let trait_bounds: Vec<TraitBound> = type_param
+ .bounds
+ .iter()
+ .flat_map(|bound| match bound {
+ TypeParamBound::Trait(trait_bound) => Some(trait_bound),
+ _ => None,
+ })
+ .cloned()
+ .collect();
+ (type_param.ident.clone(), trait_bounds)
+ })
+ .collect();
+
+ // Add trait bounds from `where` clauses, which may be type parameters or types containing
+ // those parameters.
+ for predicate in where_clause.predicates.iter() {
+ // We only care about type and not lifetime constraints here.
+ if let WherePredicate::Type(ref pred_ty) = predicate {
+ let ident = match &pred_ty.bounded_ty {
+ Type::Path(TypePath { path, qself: None }) => match path.get_ident() {
+ None => continue,
+ Some(ident) => ident,
+ },
+ _ => continue,
+ };
+ // We ignore any type constraints that aren't direct references to type
+ // parameters of the current enum of struct definition. No types can be
+ // constrained in a `where` clause unless they are a type parameter or a generic
+ // type instantiated with one of the type parameters, so by only allowing single
+ // identifiers, we can be sure that the constrained type is a type parameter
+ // that is contained in `param_constraint_mapping`.
+ if let Some((_, ref mut known_bounds)) = param_constraint_mapping
+ .iter_mut()
+ .find(|(id, _)| *id == ident)
+ {
+ for bound in pred_ty.bounds.iter() {
+ // We only care about trait bounds here.
+ if let TypeParamBound::Trait(ref bound) = bound {
+ known_bounds.push(bound.clone());
+ }
+ }
+ }
+ }
+ }
+
+ param_constraint_mapping
+}
+
+/// Hygienically add `where _: Display` to the set of [TypeParamBound]s for `ident`, creating such
+/// a set if necessary.
+fn ensure_display_in_where_clause_for_type(where_clause: &mut WhereClause, ident: Ident) {
+ for pred_ty in where_clause
+ .predicates
+ .iter_mut()
+ // Find the `where` predicate constraining the current type param, if it exists.
+ .flat_map(|predicate| match predicate {
+ WherePredicate::Type(pred_ty) => Some(pred_ty),
+ // We're looking through type constraints, not lifetime constraints.
+ _ => None,
+ })
+ {
+ // Do a complicated destructuring in order to check if the type being constrained in this
+ // `where` clause is the type we're looking for, so we can use the mutable reference to
+ // `pred_ty` if so.
+ let matches_desired_type = matches!(
+ &pred_ty.bounded_ty,
+ Type::Path(TypePath { path, .. }) if Some(&ident) == path.get_ident());
+ if matches_desired_type {
+ add_display_constraint_to_type_predicate(pred_ty);
+ return;
+ }
+ }
+
+ // If there is no `where` predicate for the current type param, we will construct one.
+ let mut new_type_predicate = new_empty_where_type_predicate(ident);
+ add_display_constraint_to_type_predicate(&mut new_type_predicate);
+ append_where_clause_type_predicate(where_clause, new_type_predicate);
+}
+
+/// For all declared type parameters, add a [core::fmt::Display] constraint, unless the type
+/// parameter already has any type constraint.
+fn ensure_where_clause_has_display_for_all_unconstrained_members(
+ where_clause: &mut WhereClause,
+ type_params: &[&TypeParam],
+) {
+ let param_constraint_mapping = extract_trait_constraints_from_source(where_clause, type_params);
+
+ for (ident, known_bounds) in param_constraint_mapping.into_iter() {
+ // If the type parameter has any constraints already, we don't want to touch it, to avoid
+ // breaking use cases where a type parameter only needs to impl `Debug`, for example.
+ if known_bounds.is_empty() {
+ ensure_display_in_where_clause_for_type(where_clause, ident);
+ }
+ }
+}
+
+/// Generate a `where` clause that ensures all generic type parameters `impl`
+/// [core::fmt::Display] unless already constrained.
+///
+/// This approach allows struct/enum definitions deriving [crate::Display] to avoid hardcoding
+/// a [core::fmt::Display] constraint into every type parameter.
+///
+/// If the type parameter isn't already constrained, we add a `where _: Display` clause to our
+/// display implementation to expect to be able to format every enum case or struct member.
+///
+/// In fact, we would preferably only require `where _: Display` or `where _: Debug` where the
+/// format string actually requires it. However, while [`std::fmt` defines a formal syntax for
+/// `format!()`][format syntax], it *doesn't* expose the actual logic to parse the format string,
+/// which appears to live in [`rustc_parse_format`]. While we use the [`syn`] crate to parse rust
+/// syntax, it also doesn't currently provide any method to introspect a `format!()` string. It
+/// would be nice to contribute this upstream in [`syn`].
+///
+/// [format syntax]: std::fmt#syntax
+/// [`rustc_parse_format`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse_format/index.html
+fn generate_where_clause(generics: &Generics, where_clause: Option<&WhereClause>) -> WhereClause {
+ let mut where_clause = where_clause.cloned().unwrap_or_else(new_empty_where_clause);
+ let type_params: Vec<&TypeParam> = generics.type_params().collect();
+ ensure_where_clause_has_display_for_all_unconstrained_members(&mut where_clause, &type_params);
+ where_clause
+}
+
+fn impl_enum(input: &DeriveInput, data: &DataEnum) -> Result<TokenStream> {
+ let ty = &input.ident;
+ let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+ let where_clause = generate_where_clause(&input.generics, where_clause);
+
+ let helper = AttrsHelper::new(&input.attrs);
+
+ let displays = data
+ .variants
+ .iter()
+ .map(|variant| helper.display_with_input(&input.attrs, &variant.attrs))
+ .collect::<Result<Vec<_>>>()?;
+
+ if data.variants.is_empty() {
+ Ok(quote! {
+ impl #impl_generics core::fmt::Display for #ty #ty_generics #where_clause {
+ fn fmt(&self, formatter: &mut core::fmt::Formatter) -> core::fmt::Result {
+ unreachable!("empty enums cannot be instantiated and thus cannot be printed")
+ }
+ }
+ })
+ } else if displays.iter().any(Option::is_some) {
+ let arms = data
+ .variants
+ .iter()
+ .zip(displays)
+ .map(|(variant, display)| {
+ let display =
+ display.ok_or_else(|| Error::new_spanned(variant, "missing doc comment"))?;
+ let ident = &variant.ident;
+ Ok(match &variant.fields {
+ Fields::Named(fields) => {
+ let var = fields.named.iter().map(|field| &field.ident);
+ quote!(Self::#ident { #(#var),* } => { #display })
+ }
+ Fields::Unnamed(fields) => {
+ let var = (0..fields.unnamed.len()).map(|i| format_ident!("_{}", i));
+ quote!(Self::#ident(#(#var),*) => { #display })
+ }
+ Fields::Unit => quote!(Self::#ident => { #display }),
+ })
+ })
+ .collect::<Result<Vec<_>>>()?;
+ Ok(quote! {
+ impl #impl_generics core::fmt::Display for #ty #ty_generics #where_clause {
+ fn fmt(&self, formatter: &mut core::fmt::Formatter) -> core::fmt::Result {
+ #[allow(unused_variables)]
+ match self {
+ #(#arms,)*
+ }
+ }
+ }
+ })
+ } else {
+ Err(Error::new_spanned(input, "Missing doc comments"))
+ }
+}
diff --git a/src/fmt.rs b/src/fmt.rs
new file mode 100644
index 0000000..3334a82
--- /dev/null
+++ b/src/fmt.rs
@@ -0,0 +1,159 @@
+use crate::attr::Display;
+use proc_macro2::TokenStream;
+use quote::quote_spanned;
+use syn::{Ident, LitStr};
+
+macro_rules! peek_next {
+ ($read:ident) => {
+ match $read.chars().next() {
+ Some(next) => next,
+ None => return,
+ }
+ };
+}
+
+impl Display {
+ // Transform `"error {var}"` to `"error {}", var`.
+ pub(crate) fn expand_shorthand(&mut self) {
+ let span = self.fmt.span();
+ let fmt = self.fmt.value();
+ let mut read = fmt.as_str();
+ let mut out = String::new();
+ let mut args = TokenStream::new();
+
+ while let Some(brace) = read.find('{') {
+ out += &read[..=brace];
+ read = &read[brace + 1..];
+
+ // skip cases where we find a {{
+ if read.starts_with('{') {
+ out.push('{');
+ read = &read[1..];
+ continue;
+ }
+
+ let next = peek_next!(read);
+
+ let var = match next {
+ '0'..='9' => take_int(&mut read),
+ 'a'..='z' | 'A'..='Z' | '_' => take_ident(&mut read),
+ _ => return,
+ };
+
+ let ident = Ident::new(&var, span);
+
+ let next = peek_next!(read);
+
+ let arg = if cfg!(feature = "std") && next == '}' {
+ quote_spanned!(span=> , #ident.__displaydoc_display())
+ } else {
+ quote_spanned!(span=> , #ident)
+ };
+
+ args.extend(arg);
+ }
+
+ out += read;
+ self.fmt = LitStr::new(&out, self.fmt.span());
+ self.args = args;
+ }
+}
+
+fn take_int(read: &mut &str) -> String {
+ let mut int = String::new();
+ int.push('_');
+ for (i, ch) in read.char_indices() {
+ match ch {
+ '0'..='9' => int.push(ch),
+ _ => {
+ *read = &read[i..];
+ break;
+ }
+ }
+ }
+ int
+}
+
+fn take_ident(read: &mut &str) -> String {
+ let mut ident = String::new();
+ for (i, ch) in read.char_indices() {
+ match ch {
+ 'a'..='z' | 'A'..='Z' | '0'..='9' | '_' => ident.push(ch),
+ _ => {
+ *read = &read[i..];
+ break;
+ }
+ }
+ }
+ ident
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use pretty_assertions::assert_eq;
+ use proc_macro2::Span;
+
+ fn assert(input: &str, fmt: &str, args: &str) {
+ let mut display = Display {
+ fmt: LitStr::new(input, Span::call_site()),
+ args: TokenStream::new(),
+ };
+ display.expand_shorthand();
+ assert_eq!(fmt, display.fmt.value());
+ assert_eq!(args, display.args.to_string());
+ }
+
+ #[test]
+ fn test_expand() {
+ assert("fn main() {{ }}", "fn main() {{ }}", "");
+ }
+
+ #[test]
+ #[cfg_attr(not(feature = "std"), ignore)]
+ fn test_std_expand() {
+ assert(
+ "{v} {v:?} {0} {0:?}",
+ "{} {:?} {} {:?}",
+ ", v . __displaydoc_display () , v , _0 . __displaydoc_display () , _0",
+ );
+ assert("error {var}", "error {}", ", var . __displaydoc_display ()");
+
+ assert(
+ "error {var1}",
+ "error {}",
+ ", var1 . __displaydoc_display ()",
+ );
+
+ assert(
+ "error {var1var}",
+ "error {}",
+ ", var1var . __displaydoc_display ()",
+ );
+
+ assert(
+ "The path {0}",
+ "The path {}",
+ ", _0 . __displaydoc_display ()",
+ );
+ assert("The path {0:?}", "The path {:?}", ", _0");
+ }
+
+ #[test]
+ #[cfg_attr(feature = "std", ignore)]
+ fn test_nostd_expand() {
+ assert(
+ "{v} {v:?} {0} {0:?}",
+ "{} {:?} {} {:?}",
+ ", v , v , _0 , _0",
+ );
+ assert("error {var}", "error {}", ", var");
+
+ assert("The path {0}", "The path {}", ", _0");
+ assert("The path {0:?}", "The path {:?}", ", _0");
+
+ assert("error {var1}", "error {}", ", var1");
+
+ assert("error {var1var}", "error {}", ", var1var");
+ }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..e4653d6
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,187 @@
+//! This library provides a convenient derive macro for the standard library's
+//! [`core::fmt::Display`] trait.
+//!
+//! [`core::fmt::Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html
+//!
+//! ```toml
+//! [dependencies]
+//! displaydoc = "0.2"
+//! ```
+//!
+//! *Compiler support: requires rustc 1.56+*
+//!
+//! <br>
+//!
+//! ## Example
+//!
+//! *Demonstration alongside the [`Error`][std::error::Error] derive macro from [`thiserror`](https://docs.rs/thiserror/1.0.25/thiserror/index.html),
+//! to propagate source locations from [`io::Error`][std::io::Error] with the `#[source]` attribute:*
+//! ```rust
+//! use std::io;
+//! use displaydoc::Display;
+//! use thiserror::Error;
+//!
+//! #[derive(Display, Error, Debug)]
+//! pub enum DataStoreError {
+//! /// data store disconnected
+//! Disconnect(#[source] io::Error),
+//! /// the data for key `{0}` is not available
+//! Redaction(String),
+//! /// invalid header (expected {expected:?}, found {found:?})
+//! InvalidHeader {
+//! expected: String,
+//! found: String,
+//! },
+//! /// unknown data store error
+//! Unknown,
+//! }
+//!
+//! let error = DataStoreError::Redaction("CLASSIFIED CONTENT".to_string());
+//! assert!("the data for key `CLASSIFIED CONTENT` is not available" == &format!("{}", error));
+//! ```
+//! *Note that although [`io::Error`][std::io::Error] implements `Display`, we do not add it to the
+//! generated message for `DataStoreError::Disconnect`, since it is already made available via
+//! `#[source]`. See further context on avoiding duplication in error reports at the rust blog
+//! [here](https://github.com/yaahc/blog.rust-lang.org/blob/master/posts/inside-rust/2021-05-15-What-the-error-handling-project-group-is-working-towards.md#duplicate-information-issue).*
+//!
+//! <br>
+//!
+//! ## Details
+//!
+//! - A `fmt::Display` impl is generated for your enum if you provide
+//! a docstring comment on each variant as shown above in the example. The
+//! `Display` derive macro supports a shorthand for interpolating fields from
+//! the error:
+//! - `/// {var}` ⟶ `write!("{}", self.var)`
+//! - `/// {0}` ⟶ `write!("{}", self.0)`
+//! - `/// {var:?}` ⟶ `write!("{:?}", self.var)`
+//! - `/// {0:?}` ⟶ `write!("{:?}", self.0)`
+//! - This also works with structs and [generic types][crate::Display#generic-type-parameters]:
+//! ```rust
+//! # use displaydoc::Display;
+//! /// oh no, an error: {0}
+//! #[derive(Display)]
+//! pub struct Error<E>(pub E);
+//!
+//! let error: Error<&str> = Error("muahaha i am an error");
+//! assert!("oh no, an error: muahaha i am an error" == &format!("{}", error));
+//! ```
+//!
+//! - Two optional attributes can be added to your types next to the derive:
+//!
+//! - `#[ignore_extra_doc_attributes]` makes the macro ignore any doc
+//! comment attributes (or `///` lines) after the first. Multi-line
+//! comments using `///` are otherwise treated as an error, so use this
+//! attribute or consider switching to block doc comments (`/** */`).
+//!
+//! - `#[prefix_enum_doc_attributes]` combines the doc comment message on
+//! your enum itself with the messages for each variant, in the format
+//! “enum: variant”. When added to an enum, the doc comment on the enum
+//! becomes mandatory. When added to any other type, it has no effect.
+//!
+//! - In case you want to have an independent doc comment, the
+//! `#[displaydoc("...")` atrribute may be used on the variant or struct to
+//! override it.
+//!
+//! <br>
+//!
+//! ## FAQ
+//!
+//! 1. **Is this crate `no_std` compatible?**
+//! * Yes! This crate implements the [`core::fmt::Display`] trait, not the [`std::fmt::Display`] trait, so it should work in `std` and `no_std` environments. Just add `default-features = false`.
+//!
+//! 2. **Does this crate work with `Path` and `PathBuf` via the `Display` trait?**
+//! * Yuuup. This crate uses @dtolnay's [autoref specialization technique](https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md) to add a special trait for types to get the display impl. It then specializes for `Path` and `PathBuf`, and when either of these types are found, it calls `self.display()` to get a `std::path::Display<'_>` type which can be used with the `Display` format specifier!
+#![doc(html_root_url = "https://docs.rs/displaydoc/0.2.3")]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![warn(
+ rust_2018_idioms,
+ unreachable_pub,
+ bad_style,
+ dead_code,
+ improper_ctypes,
+ non_shorthand_field_patterns,
+ no_mangle_generic_items,
+ overflowing_literals,
+ path_statements,
+ patterns_in_fns_without_body,
+ private_in_public,
+ unconditional_recursion,
+ unused,
+ unused_allocation,
+ unused_comparisons,
+ unused_parens,
+ while_true
+)]
+#![allow(clippy::try_err)]
+
+#[allow(unused_extern_crates)]
+extern crate proc_macro;
+
+mod attr;
+mod expand;
+mod fmt;
+
+use proc_macro::TokenStream;
+use syn::{parse_macro_input, DeriveInput};
+
+/// [Custom `#[derive(...)]` macro](https://doc.rust-lang.org/edition-guide/rust-2018/macros/custom-derive.html)
+/// for implementing [`fmt::Display`][core::fmt::Display] via doc comment attributes.
+///
+/// ### Generic Type Parameters
+///
+/// Type parameters to an enum or struct using this macro should *not* need to
+/// have an explicit `Display` constraint at the struct or enum definition
+/// site. A `Display` implementation for the `derive`d struct or enum is
+/// generated assuming each type parameter implements `Display`, but that should
+/// be possible without adding the constraint to the struct definition itself:
+/// ```rust
+/// use displaydoc::Display;
+///
+/// /// oh no, an error: {0}
+/// #[derive(Display)]
+/// pub struct Error<E>(pub E);
+///
+/// // No need to require `E: Display`, since `displaydoc::Display` adds that implicitly.
+/// fn generate_error<E>(e: E) -> Error<E> { Error(e) }
+///
+/// assert!("oh no, an error: muahaha" == &format!("{}", generate_error("muahaha")));
+/// ```
+///
+/// ### Using [`Debug`][core::fmt::Debug] Implementations with Type Parameters
+/// However, if a type parameter must instead be constrained with the
+/// [`Debug`][core::fmt::Debug] trait so that some field may be printed with
+/// `{:?}`, that constraint must currently still also be specified redundantly
+/// at the struct or enum definition site. If a struct or enum field is being
+/// formatted with `{:?}` via [`displaydoc`][crate], and a generic type
+/// parameter must implement `Debug` to do that, then that struct or enum
+/// definition will need to propagate the `Debug` constraint to every type
+/// parameter it's instantiated with:
+/// ```rust
+/// use core::fmt::Debug;
+/// use displaydoc::Display;
+///
+/// /// oh no, an error: {0:?}
+/// #[derive(Display)]
+/// pub struct Error<E: Debug>(pub E);
+///
+/// // `E: Debug` now has to propagate to callers.
+/// fn generate_error<E: Debug>(e: E) -> Error<E> { Error(e) }
+///
+/// assert!("oh no, an error: \"cool\"" == &format!("{}", generate_error("cool")));
+///
+/// // Try this with a struct that doesn't impl `Display` at all, unlike `str`.
+/// #[derive(Debug)]
+/// pub struct Oh;
+/// assert!("oh no, an error: Oh" == &format!("{}", generate_error(Oh)));
+/// ```
+#[proc_macro_derive(
+ Display,
+ attributes(ignore_extra_doc_attributes, prefix_enum_doc_attributes, displaydoc)
+)]
+pub fn derive_error(input: TokenStream) -> TokenStream {
+ let input = parse_macro_input!(input as DeriveInput);
+ expand::derive(&input)
+ .unwrap_or_else(|err| err.to_compile_error())
+ .into()
+}
diff --git a/tests/compile_tests.rs b/tests/compile_tests.rs
new file mode 100644
index 0000000..ac7427a
--- /dev/null
+++ b/tests/compile_tests.rs
@@ -0,0 +1,29 @@
+#[allow(unused_attributes)]
+#[rustversion::attr(not(nightly), ignore)]
+#[test]
+fn no_std() {
+ let t = trybuild::TestCases::new();
+ #[cfg(not(feature = "std"))]
+ t.compile_fail("tests/no_std/without.rs");
+ #[cfg(not(feature = "std"))]
+ t.compile_fail("tests/no_std/multi_line.rs");
+ #[cfg(not(feature = "std"))]
+ t.pass("tests/no_std/multi_line_allow.rs");
+ #[cfg(not(feature = "std"))]
+ t.compile_fail("tests/no_std/enum_prefix_missing.rs");
+ #[cfg(not(feature = "std"))]
+ t.pass("tests/no_std/enum_prefix.rs");
+ #[cfg(feature = "std")]
+ t.compile_fail("tests/std/without.rs");
+ #[cfg(feature = "std")]
+ t.compile_fail("tests/std/multi_line.rs");
+ #[cfg(feature = "std")]
+ t.pass("tests/std/multi_line_allow.rs");
+ #[cfg(feature = "std")]
+ t.compile_fail("tests/std/enum_prefix_missing.rs");
+ #[cfg(feature = "std")]
+ t.pass("tests/std/enum_prefix.rs");
+ #[cfg(feature = "std")]
+ t.pass("tests/std/multiple.rs");
+ t.pass("tests/no_std/with.rs");
+}
diff --git a/tests/happy.rs b/tests/happy.rs
new file mode 100644
index 0000000..f8fde9c
--- /dev/null
+++ b/tests/happy.rs
@@ -0,0 +1,152 @@
+use displaydoc::Display;
+
+#[cfg(feature = "std")]
+use std::path::PathBuf;
+
+#[derive(Display)]
+/// Just a basic struct {thing}
+struct HappyStruct {
+ thing: &'static str,
+}
+
+#[derive(Display)]
+#[ignore_extra_doc_attributes]
+/// Just a basic struct {thing}
+/// and this line should get ignored
+struct HappyStruct2 {
+ thing: &'static str,
+}
+
+#[derive(Display)]
+enum Happy {
+ /// I really like Variant1
+ Variant1,
+ /// Variant2 is pretty swell 2
+ Variant2,
+ /// Variant3 is okay {sometimes}
+ Variant3 { sometimes: &'static str },
+ /**
+ * Variant4 wants to have a lot of lines
+ *
+ * Lets see how this works out for it
+ */
+ Variant4,
+ /// Variant5 has a parameter {0} and some regular comments
+ // A regular comment that won't get picked
+ Variant5(u32),
+
+ /// The path {0}
+ #[cfg(feature = "std")]
+ Variant6(PathBuf),
+
+ /// These docs are ignored
+ #[displaydoc("Variant7 has a parameter {0} and uses #[displaydoc]")]
+ /// These docs are also ignored
+ Variant7(u32),
+}
+
+// Used for testing indented doc comments
+mod inner_mod {
+ use super::Display;
+
+ #[derive(Display)]
+ pub enum InnerHappy {
+ /// I really like Variant1
+ Variant1,
+ /// Variant2 is pretty swell 2
+ Variant2,
+ /// Variant3 is okay {sometimes}
+ Variant3 { sometimes: &'static str },
+ /**
+ * Variant4 wants to have a lot of lines
+ *
+ * Lets see how this works out for it
+ */
+ Variant4,
+ /// Variant5 has a parameter {0} and some regular comments
+ // A regular comment that won't get picked
+ Variant5(u32),
+
+ /** what happens if we
+ * put text on the first line?
+ */
+ Variant6,
+
+ /**
+ what happens if we don't use *?
+ */
+ Variant7,
+
+ /**
+ *
+ * what about extra new lines?
+ */
+ Variant8,
+ }
+}
+
+fn assert_display<T: std::fmt::Display>(input: T, expected: &'static str) {
+ let out = format!("{}", input);
+ assert_eq!(expected, out);
+}
+
+#[test]
+fn does_it_print() {
+ assert_display(Happy::Variant1, "I really like Variant1");
+ assert_display(Happy::Variant2, "Variant2 is pretty swell 2");
+ assert_display(Happy::Variant3 { sometimes: "hi" }, "Variant3 is okay hi");
+ assert_display(
+ Happy::Variant4,
+ "Variant4 wants to have a lot of lines\n\nLets see how this works out for it",
+ );
+ assert_display(
+ Happy::Variant5(2),
+ "Variant5 has a parameter 2 and some regular comments",
+ );
+ assert_display(
+ Happy::Variant7(2),
+ "Variant7 has a parameter 2 and uses #[displaydoc]",
+ );
+ assert_display(HappyStruct { thing: "hi" }, "Just a basic struct hi");
+
+ assert_display(HappyStruct2 { thing: "hi2" }, "Just a basic struct hi2");
+
+ assert_display(inner_mod::InnerHappy::Variant1, "I really like Variant1");
+ assert_display(
+ inner_mod::InnerHappy::Variant2,
+ "Variant2 is pretty swell 2",
+ );
+ assert_display(
+ inner_mod::InnerHappy::Variant3 { sometimes: "hi" },
+ "Variant3 is okay hi",
+ );
+ assert_display(
+ inner_mod::InnerHappy::Variant4,
+ "Variant4 wants to have a lot of lines\n\nLets see how this works out for it",
+ );
+ assert_display(
+ inner_mod::InnerHappy::Variant5(2),
+ "Variant5 has a parameter 2 and some regular comments",
+ );
+ assert_display(
+ inner_mod::InnerHappy::Variant6,
+ "what happens if we\nput text on the first line?",
+ );
+ assert_display(
+ inner_mod::InnerHappy::Variant7,
+ "what happens if we don\'t use *?",
+ );
+ assert_display(
+ inner_mod::InnerHappy::Variant8,
+ "what about extra new lines?",
+ );
+}
+
+#[test]
+#[cfg(feature = "std")]
+fn does_it_print_path() {
+ assert_display(
+ Happy::Variant6(PathBuf::from("/var/log/happy")),
+ "The path /var/log/happy",
+ );
+}
diff --git a/tests/no_std/enum_prefix.rs b/tests/no_std/enum_prefix.rs
new file mode 100644
index 0000000..b8482ca
--- /dev/null
+++ b/tests/no_std/enum_prefix.rs
@@ -0,0 +1,36 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+#[prefix_enum_doc_attributes]
+enum TestType {
+ /// this variant is too
+ Variant1,
+
+ /// this variant is two
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/no_std/enum_prefix_missing.rs b/tests/no_std/enum_prefix_missing.rs
new file mode 100644
index 0000000..474073e
--- /dev/null
+++ b/tests/no_std/enum_prefix_missing.rs
@@ -0,0 +1,35 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+#[derive(Display)]
+#[prefix_enum_doc_attributes]
+enum TestType {
+ /// this variant is too
+ Variant1,
+
+ /// this variant is two
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/no_std/enum_prefix_missing.stderr b/tests/no_std/enum_prefix_missing.stderr
new file mode 100644
index 0000000..8d40232
--- /dev/null
+++ b/tests/no_std/enum_prefix_missing.stderr
@@ -0,0 +1,22 @@
+error: proc-macro derive panicked
+ --> $DIR/enum_prefix_missing.rs:22:10
+ |
+22 | #[derive(Display)]
+ | ^^^^^^^
+ |
+ = help: message: Missing doc comment on enum with #[prefix_enum_doc_attributes]. Please remove the attribute or add a doc comment to the enum itself.
+
+error[E0277]: `TestType` doesn't implement `Display`
+ --> $DIR/enum_prefix_missing.rs:32:37
+ |
+32 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^ `TestType` cannot be formatted with the default formatter
+ |
+ = help: the trait `Display` is not implemented for `TestType`
+ = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+note: required by a bound in `assert_impl_all`
+ --> $DIR/enum_prefix_missing.rs:32:1
+ |
+32 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+ = note: this error originates in the macro `static_assertions::assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/no_std/multi_line.rs b/tests/no_std/multi_line.rs
new file mode 100644
index 0000000..351f6a4
--- /dev/null
+++ b/tests/no_std/multi_line.rs
@@ -0,0 +1,37 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+enum TestType {
+ /// This one is okay
+ Variant1,
+
+ /// Multi
+ /// line
+ /// doc.
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/no_std/multi_line.stderr b/tests/no_std/multi_line.stderr
new file mode 100644
index 0000000..ae4956e
--- /dev/null
+++ b/tests/no_std/multi_line.stderr
@@ -0,0 +1,22 @@
+error: proc-macro derive panicked
+ --> $DIR/multi_line.rs:23:10
+ |
+23 | #[derive(Display)]
+ | ^^^^^^^
+ |
+ = help: message: Multi-line comments are disabled by default by displaydoc. Please consider using block doc comments (/** */) or adding the #[ignore_extra_doc_attributes] attribute to your type next to the derive.
+
+error[E0277]: `TestType` doesn't implement `Display`
+ --> $DIR/multi_line.rs:34:37
+ |
+34 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^ `TestType` cannot be formatted with the default formatter
+ |
+ = help: the trait `Display` is not implemented for `TestType`
+ = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+note: required by a bound in `assert_impl_all`
+ --> $DIR/multi_line.rs:34:1
+ |
+34 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+ = note: this error originates in the macro `static_assertions::assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/no_std/multi_line_allow.rs b/tests/no_std/multi_line_allow.rs
new file mode 100644
index 0000000..22511d9
--- /dev/null
+++ b/tests/no_std/multi_line_allow.rs
@@ -0,0 +1,38 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+#[ignore_extra_doc_attributes]
+enum TestType {
+ /// This one is okay
+ Variant1,
+
+ /// Multi
+ /// line
+ /// doc.
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/no_std/with.rs b/tests/no_std/with.rs
new file mode 100644
index 0000000..eba7460
--- /dev/null
+++ b/tests/no_std/with.rs
@@ -0,0 +1,32 @@
+#![feature(lang_items, start)]
+#![no_std]
+
+#[start]
+#[cfg(not(feature = "std"))]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+#[cfg(feature = "std")]
+fn main() {}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+struct FakeType;
+
+static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
diff --git a/tests/no_std/without.rs b/tests/no_std/without.rs
new file mode 100644
index 0000000..aab3164
--- /dev/null
+++ b/tests/no_std/without.rs
@@ -0,0 +1,28 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+struct FakeType;
+
+static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/no_std/without.stderr b/tests/no_std/without.stderr
new file mode 100644
index 0000000..afcea63
--- /dev/null
+++ b/tests/no_std/without.stderr
@@ -0,0 +1,22 @@
+warning: unused import: `displaydoc::Display`
+ --> $DIR/without.rs:20:5
+ |
+20 | use displaydoc::Display;
+ | ^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `#[warn(unused_imports)]` on by default
+
+error[E0277]: `FakeType` doesn't implement `Display`
+ --> $DIR/without.rs:25:37
+ |
+25 | static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
+ | ^^^^^^^^ `FakeType` cannot be formatted with the default formatter
+ |
+ = help: the trait `Display` is not implemented for `FakeType`
+ = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+note: required by a bound in `assert_impl_all`
+ --> $DIR/without.rs:25:1
+ |
+25 | static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+ = note: this error originates in the macro `static_assertions::assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/num_in_field.rs b/tests/num_in_field.rs
new file mode 100644
index 0000000..ab90f0d
--- /dev/null
+++ b/tests/num_in_field.rs
@@ -0,0 +1,22 @@
+/// {foo1} {foo2}
+#[derive(displaydoc::Display)]
+pub struct Test {
+ foo1: String,
+ foo2: String,
+}
+
+fn assert_display<T: std::fmt::Display>(input: T, expected: &'static str) {
+ let out = format!("{}", input);
+ assert_eq!(expected, out);
+}
+
+#[test]
+fn does_it_print() {
+ assert_display(
+ Test {
+ foo1: "hi".into(),
+ foo2: "hello".into(),
+ },
+ "hi hello",
+ );
+}
diff --git a/tests/std/enum_prefix.rs b/tests/std/enum_prefix.rs
new file mode 100644
index 0000000..b8482ca
--- /dev/null
+++ b/tests/std/enum_prefix.rs
@@ -0,0 +1,36 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+#[prefix_enum_doc_attributes]
+enum TestType {
+ /// this variant is too
+ Variant1,
+
+ /// this variant is two
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/std/enum_prefix_missing.rs b/tests/std/enum_prefix_missing.rs
new file mode 100644
index 0000000..474073e
--- /dev/null
+++ b/tests/std/enum_prefix_missing.rs
@@ -0,0 +1,35 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+#[derive(Display)]
+#[prefix_enum_doc_attributes]
+enum TestType {
+ /// this variant is too
+ Variant1,
+
+ /// this variant is two
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/std/enum_prefix_missing.stderr b/tests/std/enum_prefix_missing.stderr
new file mode 100644
index 0000000..fe4b5ef
--- /dev/null
+++ b/tests/std/enum_prefix_missing.stderr
@@ -0,0 +1,22 @@
+error: proc-macro derive panicked
+ --> $DIR/enum_prefix_missing.rs:22:10
+ |
+22 | #[derive(Display)]
+ | ^^^^^^^
+ |
+ = help: message: Missing doc comment on enum with #[prefix_enum_doc_attributes]. Please remove the attribute or add a doc comment to the enum itself.
+
+error[E0277]: `TestType` doesn't implement `std::fmt::Display`
+ --> $DIR/enum_prefix_missing.rs:32:37
+ |
+32 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^ `TestType` cannot be formatted with the default formatter
+ |
+ = help: the trait `std::fmt::Display` is not implemented for `TestType`
+ = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+note: required by a bound in `assert_impl_all`
+ --> $DIR/enum_prefix_missing.rs:32:1
+ |
+32 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+ = note: this error originates in the macro `static_assertions::assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/std/multi_line.rs b/tests/std/multi_line.rs
new file mode 100644
index 0000000..5b0f2cf
--- /dev/null
+++ b/tests/std/multi_line.rs
@@ -0,0 +1 @@
+../no_std/multi_line.rs
\ No newline at end of file
diff --git a/tests/std/multi_line.stderr b/tests/std/multi_line.stderr
new file mode 100644
index 0000000..a8b6602
--- /dev/null
+++ b/tests/std/multi_line.stderr
@@ -0,0 +1,22 @@
+error: proc-macro derive panicked
+ --> $DIR/multi_line.rs:23:10
+ |
+23 | #[derive(Display)]
+ | ^^^^^^^
+ |
+ = help: message: Multi-line comments are disabled by default by displaydoc. Please consider using block doc comments (/** */) or adding the #[ignore_extra_doc_attributes] attribute to your type next to the derive.
+
+error[E0277]: `TestType` doesn't implement `std::fmt::Display`
+ --> $DIR/multi_line.rs:34:37
+ |
+34 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^ `TestType` cannot be formatted with the default formatter
+ |
+ = help: the trait `std::fmt::Display` is not implemented for `TestType`
+ = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+note: required by a bound in `assert_impl_all`
+ --> $DIR/multi_line.rs:34:1
+ |
+34 | static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+ = note: this error originates in the macro `static_assertions::assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/std/multi_line_allow.rs b/tests/std/multi_line_allow.rs
new file mode 100644
index 0000000..22511d9
--- /dev/null
+++ b/tests/std/multi_line_allow.rs
@@ -0,0 +1,38 @@
+#![cfg_attr(not(feature = "std"), feature(lang_items, start))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg_attr(not(feature = "std"), start)]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+#[ignore_extra_doc_attributes]
+enum TestType {
+ /// This one is okay
+ Variant1,
+
+ /// Multi
+ /// line
+ /// doc.
+ Variant2,
+}
+
+static_assertions::assert_impl_all!(TestType: core::fmt::Display);
+
+#[cfg(feature = "std")]
+fn main() {}
diff --git a/tests/std/multiple.rs b/tests/std/multiple.rs
new file mode 100644
index 0000000..b0a4de0
--- /dev/null
+++ b/tests/std/multiple.rs
@@ -0,0 +1,38 @@
+#![feature(lang_items, start)]
+#![no_std]
+
+#[start]
+#[cfg(not(feature = "std"))]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+ 0
+}
+
+#[lang = "eh_personality"]
+#[no_mangle]
+#[cfg(not(feature = "std"))]
+pub extern "C" fn rust_eh_personality() {}
+
+#[panic_handler]
+#[cfg(not(feature = "std"))]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+ unsafe {
+ libc::abort();
+ }
+}
+
+#[cfg(feature = "std")]
+fn main() {}
+
+use displaydoc::Display;
+
+/// this type is pretty swell
+#[derive(Display)]
+struct FakeType;
+
+static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
+
+/// this type is pretty swell2
+#[derive(Display)]
+struct FakeType2;
+
+static_assertions::assert_impl_all!(FakeType2: core::fmt::Display);
diff --git a/tests/std/without.rs b/tests/std/without.rs
new file mode 100644
index 0000000..6b5b714
--- /dev/null
+++ b/tests/std/without.rs
@@ -0,0 +1 @@
+../no_std/without.rs
\ No newline at end of file
diff --git a/tests/std/without.stderr b/tests/std/without.stderr
new file mode 100644
index 0000000..552ae82
--- /dev/null
+++ b/tests/std/without.stderr
@@ -0,0 +1,22 @@
+warning: unused import: `displaydoc::Display`
+ --> $DIR/without.rs:20:5
+ |
+20 | use displaydoc::Display;
+ | ^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `#[warn(unused_imports)]` on by default
+
+error[E0277]: `FakeType` doesn't implement `std::fmt::Display`
+ --> $DIR/without.rs:25:37
+ |
+25 | static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
+ | ^^^^^^^^ `FakeType` cannot be formatted with the default formatter
+ |
+ = help: the trait `std::fmt::Display` is not implemented for `FakeType`
+ = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+note: required by a bound in `assert_impl_all`
+ --> $DIR/without.rs:25:1
+ |
+25 | static_assertions::assert_impl_all!(FakeType: core::fmt::Display);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+ = note: this error originates in the macro `static_assertions::assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/variantless.rs b/tests/variantless.rs
new file mode 100644
index 0000000..bc23ed4
--- /dev/null
+++ b/tests/variantless.rs
@@ -0,0 +1,6 @@
+use displaydoc::Display;
+
+#[derive(Display)]
+enum EmptyInside {}
+
+static_assertions::assert_impl_all!(EmptyInside: core::fmt::Display);
diff --git a/update-readme.sh b/update-readme.sh
new file mode 100644
index 0000000..90db1a8
--- /dev/null
+++ b/update-readme.sh
@@ -0,0 +1,5 @@
+#! /usr/bin/env bash
+
+cargo readme > ./README.md
+git add ./README.md
+git commit -m "Update readme" || true
