From 5e20a29b4fdc8a2d442d1093681b396dcb4b816b Mon Sep 17 00:00:00 2001 From: Robin Krahl Date: Tue, 7 Jan 2020 11:18:04 +0000 Subject: Add structopt dependency in version 0.3.7 This patch series replaces argparse with structopt in the argument handling code. As a first step, we need structopt as a dependency. Import subrepo structopt/:structopt at efbdda4753592e27bc430fb01f7b9650b2f3174d Import subrepo bitflags/:bitflags at 30668016aca6bd3b02c766e8347e0b4080d4c296 Import subrepo clap/:clap at 784524f7eb193e35f81082cc69454c8c21b948f7 Import subrepo heck/:heck at 093d56fbf001e1506e56dbfa38631d99b1066df1 Import subrepo proc-macro-error/:proc-macro-error at 6c4cfe79a622c5de8ae68557993542be46eacae2 Import subrepo proc-macro2/:proc-macro2 at d5d48eddca4566e5438e8a2cbed4a74e049544de Import subrepo quote/:quote at 727436c6c137b20f0f34dde5d8fda2679b9747ad Import subrepo rustversion/:rustversion at 0c5663313516263059ce9059ef81fc7a1cf655ca Import subrepo syn-mid/:syn-mid at 5d3d85414a9e6674e1857ec22a87b96e04a6851a Import subrepo syn/:syn at e87c27e87f6f4ef8919d0372bdb056d53ef0d8f3 Import subrepo textwrap/:textwrap at abcd618beae3f74841032aa5b53c1086b0a57ca2 Import subrepo unicode-segmentation/:unicode-segmentation at 637c9874c4fe0c205ff27787faf150a40295c6c3 Import subrepo unicode-width/:unicode-width at 3033826f8bf05e82724140a981d5941e48fce393 Import subrepo unicode-xid/:unicode-xid at 4baae9fffb156ba229665b972a9cd5991787ceb7 --- rustversion/README.md | 138 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 rustversion/README.md (limited to 'rustversion/README.md') diff --git a/rustversion/README.md b/rustversion/README.md new file mode 100644 index 0000000..f7fdab1 --- /dev/null +++ b/rustversion/README.md @@ -0,0 +1,138 @@ +Compiler version cfg +==================== + +[![Build Status](https://api.travis-ci.com/dtolnay/rustversion.svg?branch=master)](https://travis-ci.com/dtolnay/rustversion) +[![Latest Version](https://img.shields.io/crates/v/rustversion.svg)](https://crates.io/crates/rustversion) +[![Rust Documentation](https://img.shields.io/badge/api-rustdoc-blue.svg)](https://docs.rs/rustversion) + +This crate provides macros for conditional compilation according to rustc +compiler version, analogous to [`#[cfg(...)]`][cfg] and +[`#[cfg_attr(...)]`][cfg_attr]. + +[cfg]: https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute +[cfg_attr]: https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg_attr-attribute + +```toml +[dependencies] +rustversion = "1.0" +``` + +
+ +## Selectors + +- `#[rustversion::stable]` + —
+ True on any stable compiler. + +- `#[rustversion::stable(1.34)]` + —
+ True on exactly the specified stable compiler. + +- `#[rustversion::beta]` + —
+ True on any beta compiler. + +- `#[rustversion::nightly]` + —
+ True on any nightly compiler or dev build. + +- `#[rustversion::nightly(2019-01-01)]` + —
+ True on exactly one nightly. + +- `#[rustversion::since(1.34)]` + —
+ True on that stable release and any later compiler, including beta and + nightly. + +- `#[rustversion::since(2019-01-01)]` + —
+ True on that nightly and all newer ones. + +- `#[rustversion::before(`version or date`)]` + —
+ Negative of *#[rustversion::since(...)]*. + +- `#[rustversion::not(`selector`)]` + —
+ Negative of any selector; for example *#[rustversion::not(nightly)]*. + +- `#[rustversion::any(`selectors...`)]` + —
+ True if any of the comma-separated selectors is true; for example + *#[rustversion::any(stable, beta)]*. + +- `#[rustversion::all(`selectors...`)]` + —
+ True if all of the comma-separated selectors are true; for example + *#[rustversion::all(since(1.31), before(1.34))]*. + +- `#[rustversion::attr(`selector`, `attribute`)]` + —
+ For conditional inclusion of attributes; analogous to `cfg_attr`. + +
+ +## Use cases + +Providing additional trait impls as types are stabilized in the standard library +without breaking compatibility with older compilers; in this case Pin\ +stabilized in [Rust 1.33][pin]: + +[pin]: https://blog.rust-lang.org/2019/02/28/Rust-1.33.0.html#pinning + +```rust +#[rustversion::since(1.33)] +use std::pin::Pin; + +#[rustversion::since(1.33)] +impl MyTrait for Pin

{ + /* ... */ +} +``` + +Similar but for language features; the ability to control alignment greater than +1 of packed structs was stabilized in [Rust 1.33][packed]. + +[packed]: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1330-2019-02-28 + +```rust +#[rustversion::attr(before(1.33), repr(packed))] +#[rustversion::attr(since(1.33), repr(packed(2)))] +struct Six(i16, i32); + +fn main() { + println!("{}", std::mem::align_of::()); +} +``` + +Augmenting code with `const` as const impls are stabilized in the standard +library. This use of `const` as an attribute is recognized as a special case by +the rustversion::attr macro. + +```rust +use std::time::Duration; + +#[rustversion::attr(since(1.32), const)] +fn duration_as_days(dur: Duration) -> u64 { + dur.as_secs() / 60 / 60 / 24 +} +``` + +
+ +#### License + + +Licensed under either of Apache License, Version +2.0 or MIT license at your option. + + +
+ + +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. + -- cgit v1.2.3