]>
Commit | Line | Data |
---|---|---|
1a4d82fc JJ |
1 | // Copyright 2014 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 | ||
54a0048b | 11 | //! The Rust Prelude. |
1a4d82fc | 12 | //! |
92a42be0 SL |
13 | //! Rust comes with a variety of things in its standard library. However, if |
14 | //! you had to manually import every single thing that you used, it would be | |
15 | //! very verbose. But importing a lot of things that a program never uses isn't | |
16 | //! good either. A balance needs to be struck. | |
17 | //! | |
18 | //! The *prelude* is the list of things that Rust automatically imports into | |
19 | //! every Rust program. It's kept as small as possible, and is focused on | |
7453a54e | 20 | //! things, particularly traits, which are used in almost every single Rust |
92a42be0 SL |
21 | //! program. |
22 | //! | |
23 | //! On a technical level, Rust inserts | |
1a4d82fc JJ |
24 | //! |
25 | //! ```ignore | |
26 | //! extern crate std; | |
27 | //! ``` | |
28 | //! | |
92a42be0 | 29 | //! into the crate root of every crate, and |
1a4d82fc JJ |
30 | //! |
31 | //! ```ignore | |
32 | //! use std::prelude::v1::*; | |
33 | //! ``` | |
34 | //! | |
92a42be0 SL |
35 | //! into every module. |
36 | //! | |
37 | //! # Other preludes | |
38 | //! | |
39 | //! Preludes can be seen as a pattern to make using multiple types more | |
40 | //! convenient. As such, you'll find other preludes in the standard library, | |
41 | //! such as [`std::io::prelude`]. Various libraries in the Rust ecosystem may | |
42 | //! also define their own preludes. | |
43 | //! | |
44 | //! [`std::io::prelude`]: ../io/prelude/index.html | |
45 | //! | |
9cc50fc6 | 46 | //! The difference between 'the prelude' and these other preludes is that they |
92a42be0 | 47 | //! are not automatically `use`'d, and must be imported manually. This is still |
7453a54e | 48 | //! easier than importing all of their constituent components. |
92a42be0 SL |
49 | //! |
50 | //! # Prelude contents | |
c1a9b12d SL |
51 | //! |
52 | //! The current version of the prelude (version 1) lives in | |
92a42be0 | 53 | //! [`std::prelude::v1`], and reexports the following. |
c1a9b12d | 54 | //! |
92a42be0 SL |
55 | //! * [`std::marker`]::{[`Copy`], [`Send`], [`Sized`], [`Sync`]}. The marker |
56 | //! traits indicate fundamental properties of types. | |
57 | //! * [`std::ops`]::{[`Drop`], [`Fn`], [`FnMut`], [`FnOnce`]}. Various | |
7453a54e | 58 | //! operations for both destructors and overloading `()`. |
92a42be0 SL |
59 | //! * [`std::mem`]::[`drop`], a convenience function for explicitly dropping a |
60 | //! value. | |
61 | //! * [`std::boxed`]::[`Box`], a way to allocate values on the heap. | |
62 | //! * [`std::borrow`]::[`ToOwned`], The conversion trait that defines | |
63 | //! [`to_owned()`], the generic method for creating an owned type from a | |
64 | //! borrowed type. | |
65 | //! * [`std::clone`]::[`Clone`], the ubiquitous trait that defines [`clone()`], | |
66 | //! the method for producing a copy of a value. | |
67 | //! * [`std::cmp`]::{[`PartialEq`], [`PartialOrd`], [`Eq`], [`Ord`] }. The | |
68 | //! comparison traits, which implement the comparison operators and are often | |
69 | //! seen in trait bounds. | |
70 | //! * [`std::convert`]::{[`AsRef`], [`AsMut`], [`Into`], [`From`]}. Generic | |
71 | //! conversions, used by savvy API authors to create overloaded methods. | |
72 | //! * [`std::default`]::[`Default`], types that have default values. | |
73 | //! * [`std::iter`]::{[`Iterator`], [`Extend`], [`IntoIterator`], | |
74 | //! [`DoubleEndedIterator`], [`ExactSizeIterator`]}. Iterators of various | |
75 | //! kinds. | |
76 | //! * [`std::option`]::[`Option`]::{`self`, `Some`, `None`}. A type which | |
77 | //! expresses the presence or absence of a value. This type is so commonly | |
78 | //! used, its variants are also exported. | |
79 | //! * [`std::result`]::[`Result`]::{`self`, `Ok`, `Err`}. A type for functions | |
80 | //! that may succeed or fail. Like [`Option`], its variants are exported as | |
81 | //! well. | |
82 | //! * [`std::slice`]::[`SliceConcatExt`], a trait that exists for technical | |
83 | //! reasons, but shouldn't have to exist. It provides a few useful methods on | |
84 | //! slices. | |
85 | //! * [`std::string`]::{[`String`], [`ToString`]}, heap allocated strings. | |
86 | //! * [`std::vec`]::[`Vec`](../vec/struct.Vec.html), a growable, heap-allocated | |
87 | //! vector. | |
c1a9b12d | 88 | //! |
92a42be0 SL |
89 | //! [`AsMut`]: ../convert/trait.AsMut.html |
90 | //! [`AsRef`]: ../convert/trait.AsRef.html | |
91 | //! [`Box`]: ../boxed/struct.Box.html | |
92 | //! [`Clone`]: ../clone/trait.Clone.html | |
93 | //! [`Copy`]: ../marker/trait.Copy.html | |
94 | //! [`Default`]: ../default/trait.Default.html | |
95 | //! [`DoubleEndedIterator`]: ../iter/trait.DoubleEndedIterator.html | |
96 | //! [`Drop`]: ../ops/trait.Drop.html | |
97 | //! [`Eq`]: ../cmp/trait.Eq.html | |
98 | //! [`ExactSizeIterator`]: ../iter/trait.ExactSizeIterator.html | |
99 | //! [`Extend`]: ../iter/trait.Extend.html | |
100 | //! [`FnMut`]: ../ops/trait.FnMut.html | |
101 | //! [`FnOnce`]: ../ops/trait.FnOnce.html | |
102 | //! [`Fn`]: ../ops/trait.Fn.html | |
103 | //! [`From`]: ../convert/trait.From.html | |
104 | //! [`IntoIterator`]: ../iter/trait.IntoIterator.html | |
105 | //! [`Into`]: ../convert/trait.Into.html | |
106 | //! [`Iterator`]: ../iter/trait.Iterator.html | |
107 | //! [`Option`]: ../option/enum.Option.html | |
108 | //! [`Ord`]: ../cmp/trait.Ord.html | |
109 | //! [`PartialEq`]: ../cmp/trait.PartialEq.html | |
110 | //! [`PartialOrd`]: ../cmp/trait.PartialOrd.html | |
111 | //! [`Result`]: ../result/enum.Result.html | |
112 | //! [`Send`]: ../marker/trait.Send.html | |
113 | //! [`Sized`]: ../marker/trait.Sized.html | |
114 | //! [`SliceConcatExt`]: ../slice/trait.SliceConcatExt.html | |
115 | //! [`String`]: ../string/struct.String.html | |
116 | //! [`Sync`]: ../marker/trait.Sync.html | |
117 | //! [`ToOwned`]: ../borrow/trait.ToOwned.html | |
118 | //! [`ToString`]: ../string/trait.ToString.html | |
119 | //! [`Vec`]: ../vec/struct.Vec.html | |
120 | //! [`clone()`]: ../clone/trait.Clone.html#tymethod.clone | |
121 | //! [`drop`]: ../mem/fn.drop.html | |
122 | //! [`std::borrow`]: ../borrow/index.html | |
123 | //! [`std::boxed`]: ../boxed/index.html | |
124 | //! [`std::clone`]: ../clone/index.html | |
125 | //! [`std::cmp`]: ../cmp/index.html | |
126 | //! [`std::convert`]: ../convert/index.html | |
127 | //! [`std::default`]: ../default/index.html | |
128 | //! [`std::iter`]: ../iter/index.html | |
129 | //! [`std::marker`]: ../marker/index.html | |
130 | //! [`std::mem`]: ../mem/index.html | |
131 | //! [`std::ops`]: ../ops/index.html | |
132 | //! [`std::option`]: ../option/index.html | |
133 | //! [`std::prelude::v1`]: v1/index.html | |
134 | //! [`std::result`]: ../result/index.html | |
135 | //! [`std::slice`]: ../slice/index.html | |
136 | //! [`std::string`]: ../string/index.html | |
137 | //! [`std::vec`]: ../vec/index.html | |
138 | //! [`to_owned()`]: ../borrow/trait.ToOwned.html#tymethod.to_owned | |
c1a9b12d SL |
139 | //! [book-closures]: ../../book/closures.html |
140 | //! [book-dtor]: ../../book/drop.html | |
c1a9b12d | 141 | //! [book-enums]: ../../book/enums.html |
92a42be0 | 142 | //! [book-iter]: ../../book/iterators.html |
1a4d82fc | 143 | |
85aaf69f | 144 | #![stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 145 | |
1a4d82fc | 146 | pub mod v1; |