src/libstd/tuple.rs

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Operations on tuples
  12 //!
  13 //! To access the _N_-th element of a tuple one can use `N` itself
  14 //! as a field of the tuple.
  15 //!
  16 //! Indexing starts from zero, so `0` returns first value, `1`
  17 //! returns second value, and so on. In general, a tuple with _S_
  18 //! elements provides aforementioned fields from `0` to `S-1`.
  19 //!
  20 //! If every type inside a tuple implements one of the following
  21 //! traits, then a tuple itself also implements it.
  22 //!
  23 //! * `Clone`
  24 //! * `PartialEq`
  25 //! * `Eq`
  26 //! * `PartialOrd`
  27 //! * `Ord`
  28 //! * `Default`
  29 //!
  30 //! # Examples
  31 //!
  32 //! Accessing elements of a tuple at specified indices:
  33 //!
  34 //! ```
  35 //! let x = ("colorless",  "green", "ideas", "sleep", "furiously");
  36 //! assert_eq!(x.3, "sleep");
  37 //!
  38 //! let v = (3, 3);
  39 //! let u = (1, -5);
  40 //! assert_eq!(v.0 * u.0 + v.1 * u.1, -12);
  41 //! ```
  42 //!
  43 //! Using traits implemented for tuples:
  44 //!
  45 //! ```
  46 //! let a = (1, 2);
  47 //! let b = (3, 4);
  48 //! assert!(a != b);
  49 //!
  50 //! let c = b.clone();
  51 //! assert!(b == c);
  52 //!
  53 //! let d : (u32, f32) = Default::default();
  54 //! assert_eq!(d, (0, 0.0f32));
  55 //! ```
  56
  57 #![doc(primitive = "tuple")]
  58 #![stable(feature = "rust1", since = "1.0.0")]