src/vendor/lazy_static/README.md

   1 lazy-static.rs
   2 ==============
   3
   4 A macro for declaring lazily evaluated statics in Rust.
   5
   6 Using this macro, it is possible to have `static`s that require code to be
   7 executed at runtime in order to be initialized.
   8 This includes anything requiring heap allocations, like vectors or hash maps,
   9 as well as anything that requires non-const function calls to be computed.
  10
  11 [![Travis-CI Status](https://travis-ci.org/rust-lang-nursery/lazy-static.rs.svg?branch=master)](https://travis-ci.org/rust-lang-nursery/lazy-static.rs)
  12
  13 # Getting Started
  14
  15 [lazy-static.rs is available on crates.io](https://crates.io/crates/lazy_static).
  16 It is recommended to look there for the newest released version, as well as links to the newest builds of the docs.
  17
  18 At the point of the last update of this README, the latest published version could be used like this:
  19
  20 Add the following dependency to your Cargo manifest...
  21
  22 ```toml
  23 [dependencies]
  24 lazy_static = "0.2"
  25 ```
  26
  27 ...and see the [docs](https://docs.rs/lazy_static) for how to use it.
  28
  29 # Example
  30
  31 ```rust
  32 #[macro_use]
  33 extern crate lazy_static;
  34
  35 use std::collections::HashMap;
  36
  37 lazy_static! {
  38     static ref HASHMAP: HashMap<u32, &'static str> = {
  39         let mut m = HashMap::new();
  40         m.insert(0, "foo");
  41         m.insert(1, "bar");
  42         m.insert(2, "baz");
  43         m
  44     };
  45 }
  46
  47 fn main() {
  48     // First access to `HASHMAP` initializes it
  49     println!("The entry for `0` is \"{}\".", HASHMAP.get(&0).unwrap());
  50
  51     // Any further access to `HASHMAP` just returns the computed value
  52     println!("The entry for `1` is \"{}\".", HASHMAP.get(&1).unwrap());
  53 }
  54 ```
  55
  56 ## License
  57
  58 Licensed under either of
  59
  60  * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
  61  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
  62
  63 at your option.
  64
  65 ### Contribution
  66
  67 Unless you explicitly state otherwise, any contribution intentionally submitted
  68 for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any
  69 additional terms or conditions.