--- /dev/null
+{
+ "git": {
+ "sha1": "18bc65a094d890fe1faa5d3ccb70f12b89eabf56"
+ }
+}
--- /dev/null
+# Changelog [![Crates.io][crate-badge]][crate]
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog] and this project adheres to
+[Semantic Versioning].
+
+## [Unreleased]
+
+## [1.1.0] - 2019-11-03
+### Added
+- `assert_impl_any!` macro
+- `assert_impl_one!` macro
+- `assert_trait_sub_all!` macro
+- `assert_trait_super_all!` macro
+- Frequently asked questions to `README.md`
+
+### Fixed
+- `assert_eq_size_val!`, `const_assert_eq!`, and `const_assert_ne!` to export
+ their local inner macros. Not having this prevented them from working when
+ `use`d or called directly via `static_assertions::macro!(...)`
+
+### Removed
+- Unused `_assert_obj_safe!` from pre-1.0
+
+## [1.0.0] - 2019-10-02
+### Added
+- `assert_eq_align!` macro
+
+### Removed
+- **[breaking]** Labels from macros that needed them 🎉
+ - Made possible by [`const _`] in Rust 1.37
+- **[breaking]** `assert_impl!` macro
+
+### Fixed
+- `assert_fields!` now works for `enum` types with multiple variants
+
+### Changed
+- **[breaking]** `const_assert!` macro to only take one expression
+ - Reasoning: when custom error messages are added in the future (via
+ [`assert!`]), having the macro allow for multiple comma-separated
+ expressions may lead to ambiguity
+- **[breaking]** Trait assertions to use `Type: Trait` syntax
+- **[breaking]** Field assertions to use `Type: field1, field2` syntax
+- **[breaking]** Renamed `assert_{ne,eq}_type!` to `assert_type_{ne,eq}_all!`
+
+## [0.3.4] - 2019-06-12
+### Changed
+- Aliased `assert_impl!` to `assert_impl_all!` and deprecated `assert_impl!`
+
+### Added
+- `assert_impl_all!` as replacement to `assert_impl!`
+- `assert_not_impl_all!` and `assert_not_impl_any!` macro counterparts to
+ `assert_impl_all!`
+
+### Fixed
+- `assert_eq_type!` now works with types involving lifetimes
+
+## [0.3.3] - 2019-06-12
+### Added
+- `const_assert_ne!` macro counterpart to `const_assert_eq!`
+
+### Fixed
+- `assert_eq_type!` would pass when types can coerce via `Deref`, such as with
+ `str` and `String`
+
+## [0.3.2] - 2019-05-15
+### Added
+- A `assert_eq_type!` macro that allows for checking whether inputs are the same
+ concrete type
+- A `assert_ne_type!` macro for checking whether inputs all refer to different
+ types
+
+### Fixed
+- `const_assert!` now only takes `bool` values whereas integer (or other type)
+ values could previously be passed
+
+## [0.3.1] - 2018-11-15
+### Fixed
+- Macros that refer to other internal macros can now be imported when compiling
+ for Rust 2018 ([issue
+ #10](https://github.com/nvzqz/static-assertions-rs/issues/10))
+
+## [0.3.0] - 2018-11-14
+### Changed
+- Bumped minimum supported (automatically tested) Rust version to 1.24.0
+- Moved message parameter for `assert_cfg!()` to last argument position, making
+ it consistent with other macros
+
+### Removed
+- No need to use `macro!(label; ...)` syntax when compiling on nightly Rust and
+ enabling the `nightly` feature flag
+
+## [0.2.5] - 2017-12-12
+### Changed
+- `assert_eq_size_ptr` wraps its code inside of a closure, ensuring that the
+ unsafe code inside never runs
+- Clippy no longer warns about `unneeded_field_pattern` within `assert_fields`
+
+### Added
+- Much better documentation with test examples that are guaranteed to fail at
+ compile-time
+
+### Removed
+- Removed testing features; compile failure tests are now done via doc tests
+
+## [0.2.4] - 2017-12-11
+### Removed
+- Removed the actual call to `mem::transmute` while still utilizing it for size
+ verification ([Simon Sapin], [#5])
+
+### Added
+- `assert_cfg` macro that asserts that the given configuration is set
+- `assert_fields` macro to assert that a struct type or enum variant has a given
+ field
+
+### Fixed
+- Allow more generics flexibility in `assert_impl`
+
+## [0.2.3] - 2017-08-24
+### Fixed
+- Trailing commas are now allowed
+
+### Removed
+- Removed clippy warnings
+
+## [0.2.2] - 2017-08-13
+### Added
+- Added `assert_impl` macro to ensure a type implements a given set of traits
+
+## [0.2.1] - 2017-08-13
+### Added
+- Added `assert_obj_safe` macro for ensuring that a trait is object-safe
+
+## [0.2.0] - 2017-08-12
+### Added
+- Added `assert_eq_size_ptr` macro
+
+### Fixed
+- Allow `assert_eq_size`, `const_assert`, and `const_assert_eq` in non-function
+ contexts via providing a unique label [#1]
+
+### Removed
+- **[Breaking]** Semicolon-separated `assert_eq_size` is no longer allowed
+
+## [0.1.1] - 2017-08-12
+### Added
+- Added `const_assert_eq` macro
+
+## 0.1.0 - 2017-08-12
+
+Initial release
+
+[Simon Sapin]: https://github.com/SimonSapin
+
+[`assert!`]: https://doc.rust-lang.org/stable/std/macro.assert.html
+[`const _`]: https://github.com/rust-lang/rfcs/blob/master/text/2526-const-wildcard.md
+
+[#1]: https://github.com/nvzqz/static-assertions-rs/issues/1
+[#5]: https://github.com/nvzqz/static-assertions-rs/pull/5
+
+[crate]: https://crates.io/crates/static_assertions
+[crate-badge]: https://img.shields.io/crates/v/static_assertions.svg
+
+[Keep a Changelog]: http://keepachangelog.com/en/1.0.0/
+[Semantic Versioning]: http://semver.org/spec/v2.0.0.html
+
+[Unreleased]: https://github.com/nvzqz/static-assertions-rs/compare/v1.1.0...HEAD
+[1.1.0]: https://github.com/nvzqz/static-assertions-rs/compare/v1.0.0...v1.1.0
+[1.0.0]: https://github.com/nvzqz/static-assertions-rs/compare/v0.3.4...v1.0.0
+[0.3.4]: https://github.com/nvzqz/static-assertions-rs/compare/v0.3.3...v0.3.4
+[0.3.3]: https://github.com/nvzqz/static-assertions-rs/compare/v0.3.2...v0.3.3
+[0.3.2]: https://github.com/nvzqz/static-assertions-rs/compare/v0.3.1...v0.3.2
+[0.3.1]: https://github.com/nvzqz/static-assertions-rs/compare/v0.3.0...v0.3.1
+[0.3.0]: https://github.com/nvzqz/static-assertions-rs/compare/v0.2.5...v0.3.0
+[0.2.5]: https://github.com/nvzqz/static-assertions-rs/compare/v0.2.4...v0.2.5
+[0.2.4]: https://github.com/nvzqz/static-assertions-rs/compare/v0.2.3...v0.2.4
+[0.2.3]: https://github.com/nvzqz/static-assertions-rs/compare/v0.2.2...v0.2.3
+[0.2.2]: https://github.com/nvzqz/static-assertions-rs/compare/v0.2.1...v0.2.2
+[0.2.1]: https://github.com/nvzqz/static-assertions-rs/compare/v0.2.0...v0.2.1
+[0.2.0]: https://github.com/nvzqz/static-assertions-rs/compare/v0.1.1...v0.2.0
+[0.1.1]: https://github.com/nvzqz/static-assertions-rs/compare/v0.1.0...v0.1.1
--- /dev/null
+# 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]
+name = "static_assertions"
+version = "1.1.0"
+authors = ["Nikolai Vazquez"]
+include = ["Cargo.toml", "src/**/*.rs", "README.md", "CHANGELOG.md", "LICENSE*"]
+description = "Compile-time assertions to ensure that invariants are met."
+homepage = "https://github.com/nvzqz/static-assertions-rs"
+documentation = "https://docs.rs/static_assertions/"
+readme = "README.md"
+keywords = ["assert", "static", "testing"]
+categories = ["no-std", "rust-patterns", "development-tools::testing"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/nvzqz/static-assertions-rs"
+
+[features]
+nightly = []
+[badges.is-it-maintained-issue-resolution]
+repository = "nvzqz/static-assertions-rs"
+
+[badges.is-it-maintained-open-issues]
+repository = "nvzqz/static-assertions-rs"
+
+[badges.maintenance]
+status = "passively-maintained"
+
+[badges.travis-ci]
+repository = "nvzqz/static-assertions-rs"
--- /dev/null
+[package]
+name = "static_assertions"
+version = "1.1.0"
+authors = ["Nikolai Vazquez"]
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+homepage = "https://github.com/nvzqz/static-assertions-rs"
+repository = "https://github.com/nvzqz/static-assertions-rs"
+documentation = "https://docs.rs/static_assertions/"
+categories = ["no-std", "rust-patterns", "development-tools::testing"]
+keywords = ["assert", "static", "testing"]
+description = "Compile-time assertions to ensure that invariants are met."
+include = ["Cargo.toml", "src/**/*.rs", "README.md", "CHANGELOG.md", "LICENSE*"]
+
+[badges]
+travis-ci = { repository = "nvzqz/static-assertions-rs" }
+is-it-maintained-open-issues = { repository = "nvzqz/static-assertions-rs" }
+is-it-maintained-issue-resolution = { repository = "nvzqz/static-assertions-rs" }
+maintenance = { status = "passively-maintained" }
+
+[features]
+nightly = []
--- /dev/null
+
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+
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--- /dev/null
+MIT License
+
+Copyright (c) 2017 Nikolai Vazquez
+
+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
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+copies or substantial portions of the Software.
+
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+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.
--- /dev/null
+[](https://github.com/nvzqz/static-assertions-rs)
+
+<div align="center">
+ <a href="https://crates.io/crates/static_assertions">
+ <img src="https://img.shields.io/crates/v/static_assertions.svg" alt="Crates.io">
+ <img src="https://img.shields.io/crates/d/static_assertions.svg" alt="Downloads">
+ </a>
+ <a href="https://travis-ci.org/nvzqz/static-assertions-rs">
+ <img src="https://travis-ci.org/nvzqz/static-assertions-rs.svg?branch=master" alt="Build Status">
+ </a>
+ <img src="https://img.shields.io/badge/rustc-^1.37.0-blue.svg" alt="rustc ^1.37.0">
+ <br>
+ <a href="https://www.patreon.com/nvzqz">
+ <img src="https://c5.patreon.com/external/logo/become_a_patron_button.png" alt="Become a Patron!" height="35">
+ </a>
+ <a href="https://www.paypal.me/nvzqz">
+ <img src="https://buymecoffee.intm.org/img/button-paypal-white.png" alt="Buy me a coffee" height="35">
+ </a>
+</div>
+
+Compile-time assertions for Rust, brought to you by
+[Nikolai Vazquez](https://twitter.com/NikolaiVazquez).
+
+This library lets you ensure correct assumptions about constants, types, and
+more. See the [docs] and [FAQ](#faq) for more info!
+
+## Installation
+
+This crate is available
+[on crates.io](https://crates.io/crates/static_assertions) and can be used by
+adding the following to your project's
+[`Cargo.toml`](https://doc.rust-lang.org/cargo/reference/manifest.html):
+
+```toml
+[dependencies]
+static_assertions = "1.1.0"
+```
+
+and this to your crate root (`main.rs` or `lib.rs`):
+
+```rust
+#[macro_use]
+extern crate static_assertions;
+```
+
+## Usage
+
+This crate exposes the following macros:
+- [`assert_cfg!`]
+- [`assert_eq_align!`]
+- [`assert_eq_size!`]
+- [`assert_eq_size_ptr!`]
+- [`assert_eq_size_val!`]
+- [`assert_fields!`]
+- [`assert_impl_all!`]
+- [`assert_impl_any!`]
+- [`assert_impl_one!`]
+- [`assert_not_impl_all!`]
+- [`assert_not_impl_any!`]
+- [`assert_obj_safe!`]
+- [`assert_trait_sub_all!`]
+- [`assert_trait_super_all!`]
+- [`assert_type_eq_all!`]
+- [`assert_type_ne_all!`]
+- [`const_assert!`]
+- [`const_assert_eq!`]
+- [`const_assert_ne!`]
+
+## FAQ
+
+- **Q:** When would I want to use this?
+
+ **A:** This library is useful for when wanting to ensure properties of
+ constants, types, and traits.
+
+ Basic examples:
+
+ - With the release of 1.39, `str::len` can be called in a `const`
+ context. Using [`const_assert!`], one can check that a string generated from
+ elsewhere is of a given size:
+
+ ```rust
+ const DATA: &str = include_str!("path/to/string.txt");
+
+ const_assert!(DATA.len() < 512);
+ ```
+
+ - Have a type that absolutely must implement certain traits? With
+ [`assert_impl_all!`], one can ensure this:
+
+ ```rust
+ struct Foo {
+ value: // ...
+ }
+
+ assert_impl_all!(Foo: Send, Sync);
+ ```
+
+- **Q:** How can I contribute?
+
+ **A:** A couple of ways! You can:
+
+ - Attempt coming up with some form of static analysis that you'd like to see
+ implemented. Create a [new issue] and describe how you'd imagine your
+ assertion to work, with example code to demonstrate.
+
+ - Implement your own static assertion and create a [pull request].
+
+ - Give feedback. What are some pain points? Where is it unpleasant?
+
+ - Write docs. If you're familiar with how this library works, sharing your
+ knowledge with the rest its users would be great!
+
+- **Q:** Will this affect my compiled binary?
+
+ **A:** Nope! There is zero runtime cost to using this because all checks are
+ at compile-time, and so no code is emitted to run.
+
+- **Q:** Will this affect my compile times?
+
+ **A:** Likely not by anything perceivable. If this is a concern, this library
+ can be put in `dev-dependencies`:
+
+ ```toml
+ [dev-dependencies]
+ static_assertions = "1.1.0"
+ ```
+
+ and then assertions can be conditionally run behind `#[cfg(test)]`:
+
+ ```rust
+ #[cfg(test)]
+ const_assert_eq!(MEANING_OF_LIFE, 42);
+ ```
+
+ However, the assertions will only be checked when running `cargo test`. This
+ somewhat defeats the purpose of catching false static conditions up-front with
+ a compilation failure.
+
+- **Q:** What is `const _`?
+
+ **A:** It's a way of creating an unnamed constant. This is used so that macros
+ can be called from a global scope without requiring a scope-unique label. This
+ library makes use of the side effects of evaluating the `const` expression.
+ See the feature's
+ [tracking issue](https://github.com/rust-lang/rust/issues/54912)
+ and
+ [issue #1](https://github.com/nvzqz/static-assertions-rs/issues/1)
+ for more info.
+
+## Changes
+
+See [`CHANGELOG.md`](https://github.com/nvzqz/static-assertions-rs/blob/master/CHANGELOG.md)
+for a complete list of what has changed from one version to another.
+
+## License
+
+This project is released under either:
+
+- [MIT License](https://github.com/nvzqz/static-assertions-rs/blob/master/LICENSE-MIT)
+
+- [Apache License (Version 2.0)](https://github.com/nvzqz/static-assertions-rs/blob/master/LICENSE-APACHE)
+
+at your choosing.
+
+[new issue]: https://github.com/nvzqz/static-assertions-rs/issues/new
+[pull request]: https://github.com/nvzqz/static-assertions-rs/pulls
+[docs]: https://docs.rs/static_assertions
+
+[`assert_cfg!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_cfg.html
+[`assert_eq_align!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_eq_align.html
+[`assert_eq_size!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_eq_size.html
+[`assert_eq_size_ptr!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_eq_size_ptr.html
+[`assert_eq_size_val!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_eq_size_val.html
+[`assert_fields!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_fields.html
+[`assert_impl_all!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_impl_all.html
+[`assert_impl_any!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_impl_any.html
+[`assert_impl_one!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_impl_one.html
+[`assert_not_impl_all!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_not_impl_all.html
+[`assert_not_impl_any!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_not_impl_any.html
+[`assert_obj_safe!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_obj_safe.html
+[`assert_trait_sub_all!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_trait_sub_all.html
+[`assert_trait_super_all!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_trait_super_all.html
+[`assert_type_eq_all!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_type_eq_all.html
+[`assert_type_ne_all!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.assert_type_ne_all.html
+[`const_assert!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.const_assert.html
+[`const_assert_eq!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.const_assert_eq.html
+[`const_assert_ne!`]: https://docs.rs/static_assertions/1.1.0/static_assertions/macro.const_assert_ne.html
--- /dev/null
+/// Asserts that a given configuration is set.
+///
+/// # Examples
+///
+/// A project will simply fail to compile if the given configuration is not set.
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// // We're not masochists
+/// # #[cfg(not(target_pointer_width = "16"))] // Just in case
+/// assert_cfg!(not(target_pointer_width = "16"));
+/// ```
+///
+/// If a project does not support a set of configurations, you may want to
+/// report why. There is the option of providing a compile error message string:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// # #[cfg(any(unix, windows))]
+/// assert_cfg!(any(unix, windows), "There is only support for Unix or Windows");
+///
+/// // User needs to specify a database back-end
+/// # #[cfg(target_pointer_width = "0")] // Impossible
+/// assert_cfg!(all(not(all(feature = "mysql", feature = "mongodb")),
+/// any( feature = "mysql", feature = "mongodb")),
+/// "Must exclusively use MySQL or MongoDB as database back-end");
+/// ```
+///
+/// Some configurations are impossible. For example, we can't be compiling for
+/// both macOS _and_ Windows simultaneously:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_cfg!(all(target_os = "macos",
+/// target_os = "windows"),
+/// "No, that's not how it works! ಠ_ಠ");
+/// ```
+#[macro_export]
+macro_rules! assert_cfg {
+ () => {};
+ ($($cfg:meta)+, $msg:expr $(,)?) => {
+ #[cfg(not($($cfg)+))]
+ compile_error!($msg);
+ };
+ ($($cfg:tt)*) => {
+ #[cfg(not($($cfg)*))]
+ compile_error!(concat!("Cfg does not pass: ", stringify!($($cfg)*)));
+ };
+}
--- /dev/null
+/// Asserts that types are equal in alignment.
+///
+/// This is useful when ensuring that pointer arithmetic is done correctly, or
+/// when [FFI] requires a type to have the same alignment as some foreign type.
+///
+/// # Examples
+///
+/// A `usize` has the same alignment as any pointer type:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_eq_align!(usize, *const u8, *mut u8);
+/// ```
+///
+/// The following passes because `[i32; 4]` has the same alignment as `i32`:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_eq_align!([i32; 4], i32);
+/// ```
+///
+/// The following example fails to compile because `i32x4` explicitly has 4
+/// times the alignment as `[i32; 4]`:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// # #[allow(non_camel_case_types)]
+/// #[repr(align(16))]
+/// struct i32x4([i32; 4]);
+///
+/// assert_eq_align!(i32x4, [i32; 4]);
+/// ```
+///
+/// [FFI]: https://en.wikipedia.org/wiki/Foreign_function_interface
+#[macro_export]
+macro_rules! assert_eq_align {
+ ($x:ty, $($xs:ty),+ $(,)?) => {
+ const _: fn() = || {
+ // Assigned instance must match the annotated type or else it will
+ // fail to compile
+ use $crate::_core::mem::align_of;
+ $(let _: [(); align_of::<$x>()] = [(); align_of::<$xs>()];)+
+ };
+ };
+}
--- /dev/null
+/// Asserts that types are equal in size.
+///
+/// When performing operations such as pointer casts or dealing with [`usize`]
+/// versus [`u64`] versus [`u32`], the size of your types matter. That is where
+/// this macro comes into play.
+///
+/// # Alternatives
+///
+/// There also exists [`assert_eq_size_val`](macro.assert_eq_size_val.html) and
+/// [`assert_eq_size_ptr`](macro.assert_eq_size_ptr.html). Instead of specifying
+/// types to compare, values' sizes can be directly compared against each other.
+///
+/// # Examples
+///
+/// These three types, despite being very different, all have the same size:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_eq_size!([u8; 4], (u16, u16), u32);
+/// ```
+///
+/// The following example fails to compile because `u32` has 4 times the size of
+/// `u8`:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_eq_size!(u32, u8);
+/// ```
+///
+/// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html
+/// [`u64`]: https://doc.rust-lang.org/std/primitive.u64.html
+/// [`u32`]: https://doc.rust-lang.org/std/primitive.u32.html
+#[macro_export]
+macro_rules! assert_eq_size {
+ ($x:ty, $($xs:ty),+ $(,)?) => {
+ const _: fn() = || {
+ $(let _ = $crate::_core::mem::transmute::<$x, $xs>;)+
+ };
+ };
+}
+
+/// Asserts that values pointed to are equal in size.
+///
+/// # Examples
+///
+/// This especially is useful for when coercing pointers between different types
+/// and ensuring the underlying values are the same size.
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// fn operation(x: &(u32, u32), y: &[u16; 4]) {
+/// assert_eq_size_ptr!(x, y);
+/// // ...
+/// }
+/// ```
+///
+/// The following example fails to compile because byte arrays of different
+/// lengths have different sizes:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions;
+/// # fn main() {
+/// static BYTES: &[u8; 4] = &[
+/// /* ... */
+/// # 0; 4
+/// ];
+///
+/// static TABLE: &[u8; 16] = &[
+/// /* ... */
+/// # 0; 16
+/// ];
+///
+/// assert_eq_size_ptr!(BYTES, TABLE);
+/// ```
+#[macro_export]
+macro_rules! assert_eq_size_ptr {
+ ($x:expr, $($xs:expr),+ $(,)?) => {
+ #[allow(unknown_lints, unsafe_code, forget_copy, useless_transmute)]
+ let _ = || unsafe {
+ use $crate::_core::{mem, ptr};
+ let mut copy = ptr::read($x);
+ $(ptr::write(&mut copy, mem::transmute(ptr::read($xs)));)+
+ mem::forget(copy);
+ };
+ }
+}
+
+/// Asserts that values are equal in size.
+///
+/// This macro doesn't consume its arguments and thus works for
+/// non-[`Clone`]able values.
+///
+/// # Examples
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions;
+/// # fn main() {
+/// struct Byte(u8);
+///
+/// let x = 10u8;
+/// let y = Byte(42); // Works for non-cloneable types
+///
+/// assert_eq_size_val!(x, y);
+/// assert_eq_size_val!(x, y, 0u8);
+/// # }
+/// ```
+///
+/// Even though both values are 0, they are of types with different sizes:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions;
+/// # fn main() {
+/// assert_eq_size_val!(0u8, 0u32);
+/// # }
+/// ```
+///
+/// [`Clone`]: https://doc.rust-lang.org/std/clone/trait.Clone.html
+#[macro_export(local_inner_macros)]
+macro_rules! assert_eq_size_val {
+ ($x:expr, $($xs:expr),+ $(,)?) => {
+ assert_eq_size_ptr!(&$x, $(&$xs),+);
+ }
+}
--- /dev/null
+/// Asserts that the type has the given fields.
+///
+/// # Examples
+///
+/// One common use case is when types have fields defined multiple times as a
+/// result of `#[cfg]`. This can be an issue when exposing a public API.
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions;
+/// pub struct Ty {
+/// #[cfg(windows)]
+/// pub val1: u8,
+/// #[cfg(not(windows))]
+/// pub val1: usize,
+///
+/// #[cfg(unix)]
+/// pub val2: u32,
+/// #[cfg(not(unix))]
+/// pub val2: usize,
+/// }
+///
+/// // Always have `val2` regardless of OS
+/// assert_fields!(Ty: val2);
+/// ```
+///
+/// This macro even works with `enum` variants:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// enum Data {
+/// Val {
+/// id: i32,
+/// name: String,
+/// bytes: [u8; 128],
+/// },
+/// Ptr(*const u8),
+/// }
+///
+/// assert_fields!(Data::Val: id, bytes);
+/// ```
+///
+/// The following example fails to compile because [`Range`] does not have a field named `middle`:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// use std::ops::Range;
+///
+/// assert_fields!(Range<u32>: middle);
+/// ```
+///
+/// [`Range`]: https://doc.rust-lang.org/std/ops/struct.Range.html
+#[macro_export]
+macro_rules! assert_fields {
+ ($t:ident::$v:ident: $($f:ident),+) => {
+ #[allow(unknown_lints, unneeded_field_pattern)]
+ const _: fn() = || {
+ #[allow(dead_code, unreachable_patterns)]
+ fn assert(value: $t) {
+ match value {
+ $($t::$v { $f: _, .. } => {},)+
+ _ => {}
+ }
+ }
+ };
+ };
+ ($t:path: $($f:ident),+) => {
+ #[allow(unknown_lints, unneeded_field_pattern)]
+ const _: fn() = || {
+ $(let $t { $f: _, .. };)+
+ };
+ };
+}
--- /dev/null
+/// Asserts that the type implements exactly one in a set of traits.
+///
+/// Related:
+/// - [`assert_impl_any!`]
+/// - [`assert_impl_all!`]
+/// - [`assert_not_impl_all!`]
+/// - [`assert_not_impl_any!`]
+///
+/// # Examples
+///
+/// Given some type `Foo`, it is expected to implement either `Snap`, `Crackle`,
+/// or `Pop`:
+///
+/// ```compile_fail
+/// # use static_assertions::assert_impl_one; fn main() {}
+/// struct Foo;
+///
+/// trait Snap {}
+/// trait Crackle {}
+/// trait Pop {}
+///
+/// assert_impl_one!(Foo: Snap, Crackle, Pop);
+/// ```
+///
+/// If _only_ `Crackle` is implemented, the assertion passes:
+///
+/// ```
+/// # use static_assertions::assert_impl_one; fn main() {}
+/// # struct Foo;
+/// # trait Snap {}
+/// # trait Crackle {}
+/// # trait Pop {}
+/// impl Crackle for Foo {}
+///
+/// assert_impl_one!(Foo: Snap, Crackle, Pop);
+/// ```
+///
+/// If `Snap` or `Pop` is _also_ implemented, the assertion fails:
+///
+/// ```compile_fail
+/// # use static_assertions::assert_impl_one; fn main() {}
+/// # struct Foo;
+/// # trait Snap {}
+/// # trait Crackle {}
+/// # trait Pop {}
+/// # impl Crackle for Foo {}
+/// impl Pop for Foo {}
+///
+/// assert_impl_one!(Foo: Snap, Crackle, Pop);
+/// ```
+///
+/// [`assert_impl_any!`]: macro.assert_impl_any.html
+/// [`assert_impl_all!`]: macro.assert_impl_all.html
+/// [`assert_not_impl_all!`]: macro.assert_not_impl_all.html
+/// [`assert_not_impl_any!`]: macro.assert_not_impl_any.html
+#[macro_export]
+macro_rules! assert_impl_one {
+ ($x:ty: $($t:path),+ $(,)?) => {
+ const _: fn() = || {
+ // Generic trait that must be implemented for `$x` exactly once.
+ trait AmbiguousIfMoreThanOne<A> {
+ // Required for actually being able to reference the trait.
+ fn some_item() {}
+ }
+
+ // Creates multiple scoped `Token` types for each trait `$t`, over
+ // which a specialized `AmbiguousIfMoreThanOne<Token>` is
+ // implemented for every type that implements `$t`.
+ $({
+ #[allow(dead_code)]
+ struct Token;
+
+ impl<T: ?Sized + $t> AmbiguousIfMoreThanOne<Token> for T {}
+ })+
+
+ // If there is only one specialized trait impl, type inference with
+ // `_` can be resolved and this can compile. Fails to compile if
+ // `$x` implements more than one `AmbiguousIfMoreThanOne<Token>` or
+ // does not implement any at all.
+ let _ = <$x as AmbiguousIfMoreThanOne<_>>::some_item;
+ };
+ };
+}
+
+/// Asserts that the type implements _all_ of the given traits.
+///
+/// See [`assert_not_impl_all!`] for achieving the opposite effect.
+///
+/// # Examples
+///
+/// This can be used to ensure types implement auto traits such as [`Send`] and
+/// [`Sync`], as well as traits with [blanket `impl`s][blanket].
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_impl_all!(u32: Copy, Send);
+/// assert_impl_all!(&str: Into<String>);
+/// ```
+///
+/// The following example fails to compile because raw pointers do not implement
+/// [`Send`] since they cannot be moved between threads safely:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_impl_all!(*const u8: Send);
+/// ```
+///
+/// [`assert_not_impl_all!`]: macro.assert_not_impl_all.html
+/// [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html
+/// [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html
+/// [blanket]: https://doc.rust-lang.org/book/ch10-02-traits.html#using-trait-bounds-to-conditionally-implement-methods
+#[macro_export]
+macro_rules! assert_impl_all {
+ ($type:ty: $($trait:path),+ $(,)?) => {
+ const _: fn() = || {
+ // Only callable when `$type` implements all traits in `$($trait)+`.
+ fn assert_impl_all<T: ?Sized $(+ $trait)+>() {}
+ assert_impl_all::<$type>();
+ };
+ };
+}
+
+/// Asserts that the type implements _any_ of the given traits.
+///
+/// See [`assert_not_impl_any!`] for achieving the opposite effect.
+///
+/// # Examples
+///
+/// `u8` cannot be converted from `u16`, but it can be converted into `u16`:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_impl_any!(u8: From<u16>, Into<u16>);
+/// ```
+///
+/// The unit type cannot be converted from `u8` or `u16`, but it does implement
+/// [`Send`]:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_impl_any!((): From<u8>, From<u16>, Send);
+/// ```
+///
+/// The following example fails to compile because raw pointers do not implement
+/// [`Send`] or [`Sync`] since they cannot be moved or shared between threads
+/// safely:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_impl_any!(*const u8: Send, Sync);
+/// ```
+///
+/// [`assert_not_impl_any!`]: macro.assert_not_impl_any.html
+/// [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html
+/// [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html
+#[macro_export]
+macro_rules! assert_impl_any {
+ ($x:ty: $($t:path),+ $(,)?) => {
+ const _: fn() = || {
+ use $crate::_core::marker::PhantomData;
+ use $crate::_core::ops::Deref;
+
+ // Fallback to use as the first iterative assignment to `previous`.
+ let previous = AssertImplAnyFallback;
+ struct AssertImplAnyFallback;
+
+ // Ensures that blanket traits can't impersonate the method. This
+ // prevents a false positive attack where---if a blanket trait is in
+ // scope that has `_static_assertions_impl_any`---the macro will
+ // compile when it shouldn't.
+ //
+ // See https://github.com/nvzqz/static-assertions-rs/issues/19 for
+ // more info.
+ struct ActualAssertImplAnyToken;
+ trait AssertImplAnyToken {}
+ impl AssertImplAnyToken for ActualAssertImplAnyToken {}
+ fn assert_impl_any_token<T: AssertImplAnyToken>(_: T) {}
+
+ $(let previous = {
+ struct Wrapper<T, N>(PhantomData<T>, N);
+
+ // If the method for this wrapper can't be called then the
+ // compiler will insert a deref and try again. This forwards the
+ // compiler's next attempt to the previous wrapper.
+ impl<T, N> Deref for Wrapper<T, N> {
+ type Target = N;
+
+ fn deref(&self) -> &Self::Target {
+ &self.1
+ }
+ }
+
+ // This impl is bounded on the `$t` trait, so the method can
+ // only be called if `$x` implements `$t`. This is why a new
+ // `Wrapper` is defined for each `previous`.
+ impl<T: $t, N> Wrapper<T, N> {
+ fn _static_assertions_impl_any(&self) -> ActualAssertImplAnyToken {
+ ActualAssertImplAnyToken
+ }
+ }
+
+ Wrapper::<$x, _>(PhantomData, previous)
+ };)+
+
+ // Attempt to find the method that can actually be called. The found
+ // method must return a type that implements the sealed `Token`
+ // trait, this ensures that blanket trait methods can't cause this
+ // macro to compile.
+ assert_impl_any_token(previous._static_assertions_impl_any());
+ };
+ };
+}
+
+/// Asserts that the type does **not** implement _all_ of the given traits.
+///
+/// This can be used to ensure types do not implement auto traits such as
+/// [`Send`] and [`Sync`], as well as traits with [blanket `impl`s][blanket].
+///
+/// Note that the combination of all provided traits is required to not be
+/// implemented. If you want to check that none of multiple traits are
+/// implemented you should invoke [`assert_not_impl_any!`] instead.
+///
+/// # Examples
+///
+/// Although `u32` implements `From<u16>`, it does not implement `Into<usize>`:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_not_impl_all!(u32: From<u16>, Into<usize>);
+/// ```
+///
+/// The following example fails to compile since `u32` can be converted into
+/// `u64`.
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_not_impl_all!(u32: Into<u64>);
+/// ```
+///
+/// The following compiles because [`Cell`] is not both [`Sync`] _and_ [`Send`]:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// use std::cell::Cell;
+///
+/// assert_not_impl_all!(Cell<u32>: Sync, Send);
+/// ```
+///
+/// But it is [`Send`], so this fails to compile:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// # std::cell::Cell;
+/// assert_not_impl_all!(Cell<u32>: Send);
+/// ```
+///
+/// [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html
+/// [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html
+/// [`assert_not_impl_any!`]: macro.assert_not_impl_any.html
+/// [`Cell`]: https://doc.rust-lang.org/std/cell/struct.Cell.html
+/// [blanket]: https://doc.rust-lang.org/book/ch10-02-traits.html#using-trait-bounds-to-conditionally-implement-methods
+#[macro_export]
+macro_rules! assert_not_impl_all {
+ ($x:ty: $($t:path),+ $(,)?) => {
+ const _: fn() = || {
+ // Generic trait with a blanket impl over `()` for all types.
+ trait AmbiguousIfImpl<A> {
+ // Required for actually being able to reference the trait.
+ fn some_item() {}
+ }
+
+ impl<T: ?Sized> AmbiguousIfImpl<()> for T {}
+
+ // Used for the specialized impl when *all* traits in
+ // `$($t)+` are implemented.
+ #[allow(dead_code)]
+ struct Invalid;
+
+ impl<T: ?Sized $(+ $t)+> AmbiguousIfImpl<Invalid> for T {}
+
+ // If there is only one specialized trait impl, type inference with
+ // `_` can be resolved and this can compile. Fails to compile if
+ // `$x` implements `AmbiguousIfImpl<Invalid>`.
+ let _ = <$x as AmbiguousIfImpl<_>>::some_item;
+ };
+ };
+}
+
+/// Asserts that the type does **not** implement _any_ of the given traits.
+///
+/// This can be used to ensure types do not implement auto traits such as
+/// [`Send`] and [`Sync`], as well as traits with [blanket `impl`s][blanket].
+///
+/// This macro causes a compilation failure if any of the provided individual
+/// traits are implemented for the type. If you want to check that a combination
+/// of traits is not implemented you should invoke [`assert_not_impl_all!`]
+/// instead. For single traits both macros behave the same.
+///
+/// # Examples
+///
+/// If `u32` were to implement `Into` conversions for `usize` _and_ for `u8`,
+/// the following would fail to compile:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_not_impl_any!(u32: Into<usize>, Into<u8>);
+/// ```
+///
+/// This is also good for simple one-off cases:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_not_impl_any!(&'static mut u8: Copy);
+/// ```
+///
+/// The following example fails to compile since `u32` can be converted into
+/// `u64` even though it can not be converted into a `u16`:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_not_impl_any!(u32: Into<u64>, Into<u16>);
+/// ```
+///
+/// [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html
+/// [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html
+/// [`assert_not_impl_all!`]: macro.assert_not_impl_all.html
+/// [blanket]: https://doc.rust-lang.org/book/ch10-02-traits.html#using-trait-bounds-to-conditionally-implement-methods
+#[macro_export]
+macro_rules! assert_not_impl_any {
+ ($x:ty: $($t:path),+ $(,)?) => {
+ const _: fn() = || {
+ // Generic trait with a blanket impl over `()` for all types.
+ trait AmbiguousIfImpl<A> {
+ // Required for actually being able to reference the trait.
+ fn some_item() {}
+ }
+
+ impl<T: ?Sized> AmbiguousIfImpl<()> for T {}
+
+ // Creates multiple scoped `Invalid` types for each trait `$t`, over
+ // which a specialized `AmbiguousIfImpl<Invalid>` is implemented for
+ // every type that implements `$t`.
+ $({
+ #[allow(dead_code)]
+ struct Invalid;
+
+ impl<T: ?Sized + $t> AmbiguousIfImpl<Invalid> for T {}
+ })+
+
+ // If there is only one specialized trait impl, type inference with
+ // `_` can be resolved and this can compile. Fails to compile if
+ // `$x` implements any `AmbiguousIfImpl<Invalid>`.
+ let _ = <$x as AmbiguousIfImpl<_>>::some_item;
+ };
+ };
+}
--- /dev/null
+// FIXME: Link below is required to render in index
+/// Asserts that the traits support dynamic dispatch
+/// ([object-safety](https://doc.rust-lang.org/book/ch17-02-trait-objects.html#object-safety-is-required-for-trait-objects)).
+///
+/// This is useful for when changes are made to a trait that accidentally
+/// prevent it from being used as an [object]. Such a case would be adding a
+/// generic method and forgetting to add `where Self: Sized` after it. If left
+/// unnoticed, that mistake will affect crate users and break both forward and
+/// backward compatibility.
+///
+/// # Examples
+///
+/// When exposing a public API, it's important that traits that could previously
+/// use dynamic dispatch can still do so in future compatible crate versions.
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// trait MySafeTrait {
+/// fn foo(&self) -> u32;
+/// }
+///
+/// assert_obj_safe!(std::fmt::Write, MySafeTrait);
+/// ```
+///
+/// Works with traits that are not in the calling module:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// mod inner {
+/// pub trait BasicTrait {
+/// fn bar(&self);
+/// }
+/// assert_obj_safe!(BasicTrait);
+/// }
+///
+/// assert_obj_safe!(inner::BasicTrait);
+/// ```
+///
+/// The following example fails to compile because raw pointers cannot be sent
+/// between threads safely:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_impl!(*const u8, Send);
+/// ```
+///
+/// The following example fails to compile because generics without
+/// `where Self: Sized` are not allowed in [object-safe][object] trait methods:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// trait MyUnsafeTrait {
+/// fn baz<T>(&self) -> T;
+/// }
+///
+/// assert_obj_safe!(MyUnsafeTrait);
+/// ```
+///
+/// When we fix that, the previous code will compile:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// trait MyUnsafeTrait {
+/// fn baz<T>(&self) -> T where Self: Sized;
+/// }
+///
+/// assert_obj_safe!(MyUnsafeTrait);
+/// ```
+///
+/// [object]: https://doc.rust-lang.org/book/ch17-02-trait-objects.html#object-safety-is-required-for-trait-objects
+#[macro_export]
+macro_rules! assert_obj_safe {
+ ($($xs:path),+ $(,)?) => {
+ $(const _: Option<&$xs> = None;)+
+ };
+}
--- /dev/null
+/// Asserts that the trait is a child of all of the other traits.
+///
+/// Related:
+/// - [`assert_trait_super_all!`]
+///
+/// # Examples
+///
+/// All types that implement [`Copy`] must implement [`Clone`]:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_trait_sub_all!(Copy: Clone);
+/// ```
+///
+/// All types that implement [`Ord`] must implement [`PartialEq`], [`Eq`], and
+/// [`PartialOrd`]:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_trait_sub_all!(Ord: PartialEq, Eq, PartialOrd);
+/// ```
+///
+/// The following example fails to compile because [`Eq`] is not required for
+/// [`PartialOrd`]:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_trait_sub_all!(PartialOrd: Eq);
+/// ```
+///
+/// [`assert_trait_super_all!`]: macro.assert_trait_super_all.html
+///
+/// [`Copy`]: https://doc.rust-lang.org/std/marker/trait.Copy.html
+/// [`Clone`]: https://doc.rust-lang.org/std/clone/trait.Clone.html
+/// [`Ord`]: https://doc.rust-lang.org/std/cmp/trait.Ord.html
+/// [`PartialOrd`]: https://doc.rust-lang.org/std/cmp/trait.PartialOrd.html
+/// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+/// [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html
+#[macro_export]
+macro_rules! assert_trait_sub_all {
+ ($sub:path: $($super:path),+ $(,)?) => {
+ const _: () = {
+ // One scope per super-trait.
+ $({
+ #[allow(non_camel_case_types)]
+ trait __Impl_Implication: $super {}
+
+ // Can only be implemented for `$sub` types if `$super` is
+ // also implemented.
+ impl<T: $sub> __Impl_Implication for T {}
+ })+
+ };
+ };
+}
+
+/// Asserts that the trait is a parent of all of the other traits.
+///
+/// Related:
+/// - [`assert_trait_sub_all!`]
+///
+/// # Examples
+///
+/// With this, traits `A` and `B` can both be tested to require [`Copy`] on a
+/// single line:
+///
+/// ```
+/// # use static_assertions::assert_trait_super_all;
+/// trait A: Copy {}
+/// trait B: Copy {}
+///
+/// assert_trait_super_all!(Copy: A, B);
+/// ```
+///
+/// Otherwise, each sub-trait would require its own call to
+/// [`assert_trait_sub_all!`]:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// # trait A: Copy {}
+/// # trait B: Copy {}
+/// assert_trait_sub_all!(A: Copy);
+/// assert_trait_sub_all!(B: Copy);
+/// ```
+///
+/// The following example fails to compile because trait `C` does not require
+/// [`Copy`]:
+///
+/// ```compile_fail
+/// # use static_assertions::assert_trait_super_all;
+/// # trait A: Copy {}
+/// # trait B: Copy {}
+/// trait C {}
+///
+/// assert_trait_super_all!(Copy: A, B, C);
+/// ```
+///
+/// [`assert_trait_sub_all!`]: macro.assert_trait_sub_all.html
+///
+/// [`Copy`]: https://doc.rust-lang.org/std/marker/trait.Copy.html
+#[macro_export(local_inner_macros)]
+macro_rules! assert_trait_super_all {
+ ($super:path: $($sub:path),+ $(,)?) => {
+ $(assert_trait_sub_all!($sub: $super);)+
+ };
+}
--- /dev/null
+/// Asserts that _all_ types in a list are equal to each other.
+///
+/// # Examples
+///
+/// Often times, type aliases are used to express usage semantics via naming. In
+/// some cases, the underlying type may differ based on platform. However, other
+/// types like [`c_float`] will always alias the same type.
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// use std::os::raw::c_float;
+///
+/// assert_type_eq_all!(c_float, f32);
+/// ```
+///
+/// This macro can also be used to compare types that involve lifetimes! Just
+/// use `'static` in that case:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions;
+/// # fn main() {
+/// type Buf<'a> = &'a [u8];
+///
+/// assert_type_eq_all!(Buf<'static>, &'static [u8]);
+/// # }
+/// ```
+///
+/// The following example fails to compile because `String` and `str` do not
+/// refer to the same type:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_type_eq_all!(String, str);
+/// ```
+///
+/// This should also work the other way around, regardless of [`Deref`]
+/// implementations.
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_type_eq_all!(str, String);
+/// ```
+///
+/// [`c_float`]: https://doc.rust-lang.org/std/os/raw/type.c_float.html
+/// [`Deref`]: https://doc.rust-lang.org/std/ops/trait.Deref.html
+#[macro_export]
+macro_rules! assert_type_eq_all {
+ ($x:ty, $($xs:ty),+ $(,)*) => {
+ const _: fn() = || { $({
+ trait TypeEq {
+ type This: ?Sized;
+ }
+
+ impl<T: ?Sized> TypeEq for T {
+ type This = Self;
+ }
+
+ fn assert_type_eq_all<T, U>()
+ where
+ T: ?Sized + TypeEq<This = U>,
+ U: ?Sized,
+ {}
+
+ assert_type_eq_all::<$x, $xs>();
+ })+ };
+ };
+}
+
+/// Asserts that _all_ types are **not** equal to each other.
+///
+/// # Examples
+///
+/// Rust has all sorts of slices, but they represent different types of data:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// assert_type_ne_all!([u8], [u16], str);
+/// ```
+///
+/// The following example fails to compile because [`c_uchar`] is a type alias
+/// for [`u8`]:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// use std::os::raw::c_uchar;
+///
+/// assert_type_ne_all!(c_uchar, u8, u32);
+/// ```
+///
+/// [`c_uchar`]: https://doc.rust-lang.org/std/os/raw/type.c_uchar.html
+/// [`u8`]: https://doc.rust-lang.org/std/primitive.u8.html
+#[macro_export]
+macro_rules! assert_type_ne_all {
+ ($x:ty, $($y:ty),+ $(,)?) => {
+ const _: fn() = || {
+ trait MutuallyExclusive {}
+ impl MutuallyExclusive for $x {}
+ $(impl MutuallyExclusive for $y {})+
+ };
+ };
+}
--- /dev/null
+/// Asserts that constant expressions evaluate to `true`.
+///
+/// Constant expressions can be ensured to have certain properties via this
+/// macro If the expression evaluates to `false`, the file will fail to compile.
+/// This is synonymous to [`static_assert` in C++][static_assert].
+///
+/// # Alternatives
+///
+/// There also exists [`const_assert_eq`](macro.const_assert_eq.html) for
+/// validating whether a sequence of expressions are equal to one another.
+///
+/// # Examples
+///
+/// A common use case is to guarantee properties about a constant value that's
+/// generated via meta-programming.
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const VALUE: i32 = // ...
+/// # 3;
+///
+/// const_assert!(VALUE >= 2);
+/// ```
+///
+/// Inputs are type-checked as booleans:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const_assert!(!0);
+/// ```
+///
+/// Despite this being a macro, we see this produces a type error:
+///
+/// ```txt
+/// | const_assert!(!0);
+/// | ^^ expected bool, found integral variable
+/// |
+/// = note: expected type `bool`
+/// found type `{integer}`
+/// ```
+///
+/// The following fails to compile because multiplying by 5 does not have an
+/// identity property:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const_assert!(5 * 5 == 5);
+/// ```
+///
+/// [static_assert]: http://en.cppreference.com/w/cpp/language/static_assert
+#[macro_export]
+macro_rules! const_assert {
+ ($x:expr $(,)?) => {
+ #[allow(unknown_lints, eq_op)]
+ const _: [(); 0 - !{ const ASSERT: bool = $x; ASSERT } as usize] = [];
+ };
+}
+
+/// Asserts that constants are equal in value.
+///
+/// # Examples
+///
+/// This works as a shorthand for `const_assert!(a == b)`:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const TWO: usize = 2;
+///
+/// const_assert_eq!(TWO * TWO, TWO + TWO);
+/// ```
+///
+/// Just because 2 × 2 = 2 + 2 doesn't mean it holds true for other numbers:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const_assert_eq!(4 + 4, 4 * 4);
+/// ```
+#[macro_export(local_inner_macros)]
+macro_rules! const_assert_eq {
+ ($x:expr, $y:expr $(,)?) => {
+ const_assert!($x == $y);
+ };
+}
+
+/// Asserts that constants are **not** equal in value.
+///
+/// # Examples
+///
+/// This works as a shorthand for `const_assert!(a != b)`:
+///
+/// ```
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const NUM: usize = 32;
+///
+/// const_assert_ne!(NUM * NUM, 64);
+/// ```
+///
+/// The following example fails to compile because 2 is magic and 2 × 2 = 2 + 2:
+///
+/// ```compile_fail
+/// # #[macro_use] extern crate static_assertions; fn main() {}
+/// const_assert_ne!(2 + 2, 2 * 2);
+/// ```
+#[macro_export(local_inner_macros)]
+macro_rules! const_assert_ne {
+ ($x:expr, $y:expr $(,)?) => {
+ const_assert!($x != $y);
+ };
+}
--- /dev/null
+//! [](https://github.com/nvzqz/static-assertions-rs)
+//!
+//! <div align="center">
+//! <a href="https://crates.io/crates/static_assertions">
+//! <img src="https://img.shields.io/crates/d/static_assertions.svg" alt="Downloads">
+//! </a>
+//! <a href="https://travis-ci.org/nvzqz/static-assertions-rs">
+//! <img src="https://travis-ci.org/nvzqz/static-assertions-rs.svg?branch=master" alt="Build Status">
+//! </a>
+//! <img src="https://img.shields.io/badge/rustc-^1.37.0-blue.svg" alt="rustc ^1.37.0">
+//! <br><br>
+//! </div>
+//!
+//! Assertions to ensure correct assumptions about constants, types, and more.
+//!
+//! _All_ checks provided by this crate are performed at [compile-time]. This
+//! allows for finding errors quickly and early when it comes to ensuring
+//! certain features or aspects of a codebase. These macros are especially
+//! important when exposing a public API that requires types to be the same size
+//! or implement certain traits.
+//!
+//! # Usage
+//!
+//! This crate is available [on crates.io][crate] and can be used by adding the
+//! following to your project's [`Cargo.toml`]:
+//!
+//! ```toml
+//! [dependencies]
+//! static_assertions = "1.1.0"
+//! ```
+//!
+//! and this to your crate root (`main.rs` or `lib.rs`):
+//!
+//! ```
+//! #[macro_use]
+//! extern crate static_assertions;
+//! # fn main() {}
+//! ```
+//!
+//! When using [Rust 2018 edition][2018], the following shorthand can help if
+//! having `#[macro_use]` is undesirable.
+//!
+//! ```edition2018
+//! extern crate static_assertions as sa;
+//!
+//! sa::const_assert!(true);
+//! ```
+//!
+//! # Examples
+//!
+//! Very thorough examples are provided in the docs for
+//! [each individual macro](#macros). Failure case examples are also documented.
+//!
+//! # Changes
+//!
+//! See [`CHANGELOG.md`](https://github.com/nvzqz/static-assertions-rs/blob/master/CHANGELOG.md)
+//! for an exhaustive list of what has changed from one version to another.
+//!
+//! # Donate
+//!
+//! This project is made freely available (as in free beer), but unfortunately
+//! not all beer is free! So, if you would like to buy me a beer (or coffee or
+//! *more*), then consider supporting my work that's benefited your project
+//! and thousands of others.
+//!
+//! <a href="https://www.patreon.com/nvzqz">
+//! <img src="https://c5.patreon.com/external/logo/become_a_patron_button.png" alt="Become a Patron!" height="35">
+//! </a>
+//! <a href="https://www.paypal.me/nvzqz">
+//! <img src="https://buymecoffee.intm.org/img/button-paypal-white.png" alt="Buy me a coffee" height="35">
+//! </a>
+//!
+//! [Rust 1.37]: https://blog.rust-lang.org/2019/08/15/Rust-1.37.0.html
+//! [2018]: https://blog.rust-lang.org/2018/12/06/Rust-1.31-and-rust-2018.html#rust-2018
+//! [crate]: https://crates.io/crates/static_assertions
+//! [compile-time]: https://en.wikipedia.org/wiki/Compile_time
+//! [`Cargo.toml`]: https://doc.rust-lang.org/cargo/reference/manifest.html
+
+#![doc(html_root_url = "https://docs.rs/static_assertions/1.1.0")]
+#![doc(html_logo_url = "https://raw.githubusercontent.com/nvzqz/static-assertions-rs/assets/Icon.png")]
+
+#![no_std]
+
+#![deny(unused_macros)]
+
+#[doc(hidden)]
+pub extern crate core as _core;
+
+mod assert_cfg;
+mod assert_eq_align;
+mod assert_eq_size;
+mod assert_fields;
+mod assert_impl;
+mod assert_obj_safe;
+mod assert_trait;
+mod assert_type;
+mod const_assert;
projects / platform / upstream / rust-static_assertions.git / commitdiff