# Primitive Type str 1.0.0 [−]

String slices.

The `str` type, also called a 'string slice', is the most primitive string type. It is usually seen in its borrowed form, `&str`. It is also the type of string literals, `&'static str`.

Strings slices are always valid UTF-8.

This documentation describes a number of methods and trait implementations on the `str` type. For technical reasons, there is additional, separate documentation in the `std::str` module as well.

# Examples

String literals are string slices:

    let hello = "Hello, world!";

    // with an explicit type annotation
    let hello: &'static str = "Hello, world!";Run

They are `'static` because they're stored directly in the final binary, and so will be valid for the `'static` duration.

# Representation

A `&str` is made up of two components: a pointer to some bytes, and a length. You can look at these with the `.as_ptr` and `len` methods:

    use std::slice;
    use std::str;

    let story = "Once upon a time...";

    let ptr = story.as_ptr();
    let len = story.len();

    // story has nineteen bytes
    assert_eq!(19, len);

    // We can re-build a str out of ptr and len. This is all unsafe because
    // we are responsible for making sure the two components are valid:
    let s = unsafe {
        // First, we build a &[u8]...
        let slice = slice::from_raw_parts(ptr, len);

        // ... and then convert that slice into a string slice
        str::from_utf8(slice)
    };

    assert_eq!(s, Ok(story));Run

Note: This example shows the internals of `&str`. `unsafe` should not be used to get a string slice under normal circumstances. Use `.as_slice()` instead.

## Methods

### `impl str`
[src]

Methods for string slices.

#### `fn len(&self) -> usize`

Returns the length of `self`.

This length is in bytes, not `char`s or graphemes. In other words, it may not be what a human considers the length of the string.

# Examples

Basic usage:

    let len = "foo".len();
    assert_eq!(3, len);

    let len = "ƒoo".len(); // fancy f!
    assert_eq!(4, len);Run

#### `fn is_empty(&self) -> bool`

Returns `true` if `self` has a length of zero bytes.

# Examples

Basic usage:

    let s = "";
    assert!(s.is_empty());

    let s = "not empty";
    assert!(!s.is_empty());Run

#### `fn is_char_boundary(&self, index: usize) -> bool`
1.9.0

Checks that `index`-th byte lies at the start and/or end of a UTF-8 code point sequence.

The start and end of the string (when `index == self.len()`) are considered to be boundaries.

Returns `false` if `index` is greater than `self.len()`.

# Examples

    let s = "Löwe 老虎 Léopard";
    assert!(s.is_char_boundary(0));
    // start of `老`
    assert!(s.is_char_boundary(6));
    assert!(s.is_char_boundary(s.len()));

    // second byte of `ö`
    assert!(!s.is_char_boundary(2));

    // third byte of `老`
    assert!(!s.is_char_boundary(8));Run

#### `fn as_bytes(&self) -> &[u8]`

Converts a string slice to a byte slice.

# Examples

Basic usage:

    let bytes = "bors".as_bytes();
    assert_eq!(b"bors", bytes);Run

#### `fn as_ptr(&self) -> *const u8`

Converts a string slice to a raw pointer.

As string slices are a slice of bytes, the raw pointer points to a `u8`. This pointer will be pointing to the first byte of the string slice.

# Examples

Basic usage:

    let s = "Hello";
    let ptr = s.as_ptr();Run

#### `fn get<I>(&self, i: I) -> Option<&I::Output> where I: SliceIndex<str>`

🔬 This is a nightly-only experimental API. (`str_checked_slicing` #39932)

Returns a subslice of `str`.

This is the non-panicking alternative to indexing the `str`. Returns `None` whenever equivalent indexing operation would panic.

# Examples

    let v = "🗻∈🌏";
    assert_eq!(Some("🗻"), v.get(0..4));
    assert!(v.get(1..).is_none());
    assert!(v.get(..8).is_none());
    assert!(v.get(..42).is_none());Run

#### `fn get_mut<I>(&mut self, i: I) -> Option<&mut I::Output> where I: SliceIndex<str>`

🔬 This is a nightly-only experimental API. (`str_checked_slicing` #39932)

Returns a mutable subslice of `str`.

This is the non-panicking alternative to indexing the `str`. Returns `None` whenever equivalent indexing operation would panic.

# Examples

    let mut v = String::from("🗻∈🌏");
    assert_eq!(Some("🗻"), v.get_mut(0..4).map(|v| &*v));
    assert!(v.get_mut(1..).is_none());
    assert!(v.get_mut(..8).is_none());
    assert!(v.get_mut(..42).is_none());Run

#### `unsafe fn get_unchecked<I>(&self, i: I) -> &I::Output where I: SliceIndex<str>`

🔬 This is a nightly-only experimental API. (`str_checked_slicing` #39932)

Returns a unchecked subslice of `str`.

This is the unchecked alternative to indexing the `str`.

# Safety

Callers of this function are responsible that these preconditions are satisfied:

- The starting index must come before the ending index;
- Indexes must be within bounds of the original slice;
- Indexes must lie on UTF-8 sequence boundaries.

Failing that, the returned string slice may reference invalid memory or violate the invariants communicated by the `str` type.

# Examples

    let v = "🗻∈🌏";
    unsafe {
        assert_eq!("🗻", v.get_unchecked(0..4));
        assert_eq!("∈", v.get_unchecked(4..7));
        assert_eq!("🌏", v.get_unchecked(7..11));
    }Run

#### `unsafe fn get_unchecked_mut<I>(&mut self, i: I) -> &mut I::Output where I: SliceIndex<str>`

🔬 This is a nightly-only experimental API. (`str_checked_slicing` #39932)

Returns a mutable, unchecked subslice of `str`.

This is the unchecked alternative to indexing the `str`.

# Safety

Callers of this function are responsible that these preconditions are satisfied:

- The starting index must come before the ending index;
- Indexes must be within bounds of the original slice;
- Indexes must lie on UTF-8 sequence boundaries.

Failing that, the returned string slice may reference invalid memory or violate the invariants communicated by the `str` type.

# Examples

    let mut v = String::from("🗻∈🌏");
    unsafe {
        assert_eq!("🗻", v.get_unchecked_mut(0..4));
        assert_eq!("∈", v.get_unchecked_mut(4..7));
        assert_eq!("🌏", v.get_unchecked_mut(7..11));
    }Run

#### `unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str`

Creates a string slice from another string slice, bypassing safety checks.

This new slice goes from `begin` to `end`, including `begin` but excluding `end`.

To get a mutable string slice instead, see the `slice_mut_unchecked` method.

# Safety

Callers of this function are responsible that three preconditions are satisfied:

- `begin` must come before `end`.
- `begin` and `end` must be byte positions within the string slice.
- `begin` and `end` must lie on UTF-8 sequence boundaries.

# Examples

Basic usage:

    let s = "Löwe 老虎 Léopard";

    unsafe {
        assert_eq!("Löwe 老虎 Léopard", s.slice_unchecked(0, 21));
    }

    let s = "Hello, world!";

    unsafe {
        assert_eq!("world", s.slice_unchecked(7, 12));
    }Run

#### `unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str`
1.5.0

Creates a string slice from another string slice, bypassing safety checks.

This new slice goes from `begin` to `end`, including `begin` but excluding `end`.

To get an immutable string slice instead, see the `slice_unchecked` method.

# Safety

Callers of this function are responsible that three preconditions are satisfied:

- `begin` must come before `end`.
- `begin` and `end` must be byte positions within the string slice.
- `begin` and `end` must lie on UTF-8 sequence boundaries.

#### `fn split_at(&self, mid: usize) -> (&str, &str)`
1.4.0

Divide one string slice into two at an index.

The argument, `mid`, should be a byte offset from the start of the string. It must also be on the boundary of a UTF-8 code point.

The two slices returned go from the start of the string slice to `mid`, and from `mid` to the end of the string slice.

To get mutable string slices instead, see the `split_at_mut` method.

# Panics

Panics if `mid` is not on a UTF-8 code point boundary, or if it is beyond the last code point of the string slice.

# Examples

Basic usage:

    let s = "Per Martin-Löf";

    let (first, last) = s.split_at(3);

    assert_eq!("Per", first);
    assert_eq!(" Martin-Löf", last);Run

#### `fn split_at_mut(&mut self, mid: usize) -> (&mut str, &mut str)`
1.4.0

Divide one mutable string slice into two at an index.

The argument, `mid`, should be a byte offset from the start of the string. It must also be on the boundary of a UTF-8 code point.

The two slices returned go from the start of the string slice to `mid`, and from `mid` to the end of the string slice.

To get immutable string slices instead, see the `split_at` method.

# Panics

Panics if `mid` is not on a UTF-8 code point boundary, or if it is beyond the last code point of the string slice.

# Examples

Basic usage:

    let mut s = "Per Martin-Löf".to_string();

    let (first, last) = s.split_at_mut(3);

    assert_eq!("Per", first);
    assert_eq!(" Martin-Löf", last);Run

#### `fn chars(&self) -> Chars`

Returns an iterator over the `char`s of a string slice.

As a string slice consists of valid UTF-8, we can iterate through a string slice by `char`. This method returns such an iterator.

It's important to remember that `char` represents a Unicode Scalar Value, and may not match your idea of what a 'character' is. Iteration over grapheme clusters may be what you actually want.

# Examples

Basic usage:

    let word = "goodbye";

    let count = word.chars().count();
    assert_eq!(7, count);

    let mut chars = word.chars();

    assert_eq!(Some('g'), chars.next());
    assert_eq!(Some('o'), chars.next());
    assert_eq!(Some('o'), chars.next());
    assert_eq!(Some('d'), chars.next());
    assert_eq!(Some('b'), chars.next());
    assert_eq!(Some('y'), chars.next());
    assert_eq!(Some('e'), chars.next());

    assert_eq!(None, chars.next());Run

Remember, `char`s may not match your human intuition about characters:

    let y = "y̆";

    let mut chars = y.chars();

    assert_eq!(Some('y'), chars.next()); // not 'y̆'
    assert_eq!(Some('\u{0306}'), chars.next());

    assert_eq!(None, chars.next());Run

#### `fn char_indices(&self) -> CharIndices`

Returns an iterator over the `char`s of a string slice, and their positions.

As a string slice consists of valid UTF-8, we can iterate through a string slice by `char`. This method returns an iterator of both these `char`s, as well as their byte positions.

The iterator yields tuples. The position is first, the `char` is second.

# Examples

Basic usage:

    let word = "goodbye";

    let count = word.char_indices().count();
    assert_eq!(7, count);

    let mut char_indices = word.char_indices();

    assert_eq!(Some((0, 'g')), char_indices.next());
    assert_eq!(Some((1, 'o')), char_indices.next());
    assert_eq!(Some((2, 'o')), char_indices.next());
    assert_eq!(Some((3, 'd')), char_indices.next());
    assert_eq!(Some((4, 'b')), char_indices.next());
    assert_eq!(Some((5, 'y')), char_indices.next());
    assert_eq!(Some((6, 'e')), char_indices.next());

    assert_eq!(None, char_indices.next());Run

Remember, `char`s may not match your human intuition about characters:

    let y = "y̆";

    let mut char_indices = y.char_indices();

    assert_eq!(Some((0, 'y')), char_indices.next()); // not (0, 'y̆')
    assert_eq!(Some((1, '\u{0306}')), char_indices.next());

    assert_eq!(None, char_indices.next());Run

#### `fn bytes(&self) -> Bytes`

An iterator over the bytes of a string slice.

As a string slice consists of a sequence of bytes, we can iterate through a string slice by byte. This method returns such an iterator.

# Examples

Basic usage:

    let mut bytes = "bors".bytes();

    assert_eq!(Some(b'b'), bytes.next());
    assert_eq!(Some(b'o'), bytes.next());
    assert_eq!(Some(b'r'), bytes.next());
    assert_eq!(Some(b's'), bytes.next());

    assert_eq!(None, bytes.next());Run

#### `fn split_whitespace(&self) -> SplitWhitespace`
1.1.0

Split a string slice by whitespace.

The iterator returned will return string slices that are sub-slices of the original string slice, separated by any amount of whitespace.

'Whitespace' is defined according to the terms of the Unicode Derived Core Property `White_Space`.

# Examples

Basic usage:

    let mut iter = "A few words".split_whitespace();

    assert_eq!(Some("A"), iter.next());
    assert_eq!(Some("few"), iter.next());
    assert_eq!(Some("words"), iter.next());

    assert_eq!(None, iter.next());Run

All kinds of whitespace are considered:

    let mut iter = " Mary   had\ta\u{2009}little  \n\t lamb".split_whitespace();
    assert_eq!(Some("Mary"), iter.next());
    assert_eq!(Some("had"), iter.next());
    assert_eq!(Some("a"), iter.next());
    assert_eq!(Some("little"), iter.next());
    assert_eq!(Some("lamb"), iter.next());

    assert_eq!(None, iter.next());Run

#### `fn lines(&self) -> Lines`

An iterator over the lines of a string, as string slices.

Lines are ended with either a newline (`\n`) or a carriage return with a line feed (`\r\n`).

The final line ending is optional.

# Examples

Basic usage:

    let text = "foo\r\nbar\n\nbaz\n";
    let mut lines = text.lines();

    assert_eq!(Some("foo"), lines.next());
    assert_eq!(Some("bar"), lines.next());
    assert_eq!(Some(""), lines.next());
    assert_eq!(Some("baz"), lines.next());

    assert_eq!(None, lines.next());Run

The final line ending isn't required:

    let text = "foo\nbar\n\r\nbaz";
    let mut lines = text.lines();

    assert_eq!(Some("foo"), lines.next());
    assert_eq!(Some("bar"), lines.next());
    assert_eq!(Some(""), lines.next());
    assert_eq!(Some("baz"), lines.next());

    assert_eq!(None, lines.next());Run

#### `fn lines_any(&self) -> LinesAny`

Deprecated since 1.4.0

: use lines() instead now

An iterator over the lines of a string.

#### `fn encode_utf16(&self) -> EncodeUtf16`
1.8.0

Returns an iterator of `u16` over the string encoded as UTF-16.

#### `fn contains<'a, P>(&'a self, pat: P) -> bool where P: Pattern<'a>`

Returns `true` if the given pattern matches a sub-slice of this string slice.

Returns `false` if it does not.

# Examples

Basic usage:

    let bananas = "bananas";

    assert!(bananas.contains("nana"));
    assert!(!bananas.contains("apples"));Run

#### `fn starts_with<'a, P>(&'a self, pat: P) -> bool where P: Pattern<'a>`

Returns `true` if the given pattern matches a prefix of this string slice.

Returns `false` if it does not.

# Examples

Basic usage:

    let bananas = "bananas";

    assert!(bananas.starts_with("bana"));
    assert!(!bananas.starts_with("nana"));Run

#### `fn ends_with<'a, P>(&'a self, pat: P) -> bool where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`

Returns `true` if the given pattern matches a suffix of this string slice.

Returns `false` if it does not.

# Examples

Basic usage:

    let bananas = "bananas";

    assert!(bananas.ends_with("anas"));
    assert!(!bananas.ends_with("nana"));Run

#### `fn find<'a, P>(&'a self, pat: P) -> Option<usize> where P: Pattern<'a>`

Returns the byte index of the first character of this string slice that matches the pattern.

Returns `None` if the pattern doesn't match.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Examples

Simple patterns:

    let s = "Löwe 老虎 Léopard";

    assert_eq!(s.find('L'), Some(0));
    assert_eq!(s.find('é'), Some(14));
    assert_eq!(s.find("Léopard"), Some(13));Run

More complex patterns with closures:

    let s = "Löwe 老虎 Léopard";

    assert_eq!(s.find(char::is_whitespace), Some(5));
    assert_eq!(s.find(char::is_lowercase), Some(1));Run

Not finding the pattern:

    let s = "Löwe 老虎 Léopard";
    let x: &[_] = &['1', '2'];

    assert_eq!(s.find(x), None);Run

#### `fn rfind<'a, P>(&'a self, pat: P) -> Option<usize> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`

Returns the byte index of the last character of this string slice that matches the pattern.

Returns `None` if the pattern doesn't match.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Examples

Simple patterns:

    let s = "Löwe 老虎 Léopard";

    assert_eq!(s.rfind('L'), Some(13));
    assert_eq!(s.rfind('é'), Some(14));Run

More complex patterns with closures:

    let s = "Löwe 老虎 Léopard";

    assert_eq!(s.rfind(char::is_whitespace), Some(12));
    assert_eq!(s.rfind(char::is_lowercase), Some(20));Run

Not finding the pattern:

    let s = "Löwe 老虎 Léopard";
    let x: &[_] = &['1', '2'];

    assert_eq!(s.rfind(x), None);Run

#### `fn split<'a, P>(&'a self, pat: P) -> Split<'a, P> where P: Pattern<'a>`

An iterator over substrings of this string slice, separated by characters matched by a pattern.

The pattern can be a `&str`, `char`, or a closure that determines the split.

# Iterator behavior

The returned iterator will be a `DoubleEndedIterator` if the pattern allows a reverse search and forward/reverse search yields the same elements. This is true for, eg, `char` but not for `&str`.

If the pattern allows a reverse search but its results might differ from a forward search, the `rsplit` method can be used.

# Examples

Simple patterns:

    let v: Vec<&str> = "Mary had a little lamb".split(' ').collect();
    assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]);

    let v: Vec<&str> = "".split('X').collect();
    assert_eq!(v, [""]);

    let v: Vec<&str> = "lionXXtigerXleopard".split('X').collect();
    assert_eq!(v, ["lion", "", "tiger", "leopard"]);

    let v: Vec<&str> = "lion::tiger::leopard".split("::").collect();
    assert_eq!(v, ["lion", "tiger", "leopard"]);

    let v: Vec<&str> = "abc1def2ghi".split(char::is_numeric).collect();
    assert_eq!(v, ["abc", "def", "ghi"]);

    let v: Vec<&str> = "lionXtigerXleopard".split(char::is_uppercase).collect();
    assert_eq!(v, ["lion", "tiger", "leopard"]);Run

A more complex pattern, using a closure:

    let v: Vec<&str> = "abc1defXghi".split(|c| c == '1' || c == 'X').collect();
    assert_eq!(v, ["abc", "def", "ghi"]);Run

If a string contains multiple contiguous separators, you will end up with empty strings in the output:

    let x = "||||a||b|c".to_string();
    let d: Vec<_> = x.split('|').collect();

    assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]);Run

Contiguous separators are separated by the empty string.

    let x = "(///)".to_string();
    let d: Vec<_> = x.split('/').collect();;

    assert_eq!(d, &["(", "", "", ")"]);Run

Separators at the start or end of a string are neighbored by empty strings.

    let d: Vec<_> = "010".split("0").collect();
    assert_eq!(d, &["", "1", ""]);Run

When the empty string is used as a separator, it separates every character in the string, along with the beginning and end of the string.

    let f: Vec<_> = "rust".split("").collect();
    assert_eq!(f, &["", "r", "u", "s", "t", ""]);Run

Contiguous separators can lead to possibly surprising behavior when whitespace is used as the separator. This code is correct:

    let x = "    a  b c".to_string();
    let d: Vec<_> = x.split(' ').collect();

    assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]);Run

It does not give you:

    assert_eq!(d, &["a", "b", "c"]);Run

Use `split_whitespace` for this behavior.

#### `fn rsplit<'a, P>(&'a self, pat: P) -> RSplit<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`

An iterator over substrings of the given string slice, separated by characters matched by a pattern and yielded in reverse order.

The pattern can be a `&str`, `char`, or a closure that determines the split.

# Iterator behavior

The returned iterator requires that the pattern supports a reverse search, and it will be a `DoubleEndedIterator` if a forward/reverse search yields the same elements.

For iterating from the front, the `split` method can be used.

# Examples

Simple patterns:

    let v: Vec<&str> = "Mary had a little lamb".rsplit(' ').collect();
    assert_eq!(v, ["lamb", "little", "a", "had", "Mary"]);

    let v: Vec<&str> = "".rsplit('X').collect();
    assert_eq!(v, [""]);

    let v: Vec<&str> = "lionXXtigerXleopard".rsplit('X').collect();
    assert_eq!(v, ["leopard", "tiger", "", "lion"]);

    let v: Vec<&str> = "lion::tiger::leopard".rsplit("::").collect();
    assert_eq!(v, ["leopard", "tiger", "lion"]);Run

A more complex pattern, using a closure:

    let v: Vec<&str> = "abc1defXghi".rsplit(|c| c == '1' || c == 'X').collect();
    assert_eq!(v, ["ghi", "def", "abc"]);Run

#### `fn split_terminator<'a, P>(&'a self, pat: P) -> SplitTerminator<'a, P> where P: Pattern<'a>`

An iterator over substrings of the given string slice, separated by characters matched by a pattern.

The pattern can be a `&str`, `char`, or a closure that determines the split.

Equivalent to `split`, except that the trailing substring is skipped if empty.

This method can be used for string data that is terminated, rather than separated by a pattern.

# Iterator behavior

The returned iterator will be a `DoubleEndedIterator` if the pattern allows a reverse search and forward/reverse search yields the same elements. This is true for, eg, `char` but not for `&str`.

If the pattern allows a reverse search but its results might differ from a forward search, the `rsplit_terminator` method can be used.

# Examples

Basic usage:

    let v: Vec<&str> = "A.B.".split_terminator('.').collect();
    assert_eq!(v, ["A", "B"]);

    let v: Vec<&str> = "A..B..".split_terminator(".").collect();
    assert_eq!(v, ["A", "", "B", ""]);Run

#### `fn rsplit_terminator<'a, P>(&'a self, pat: P) -> RSplitTerminator<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`

An iterator over substrings of `self`, separated by characters matched by a pattern and yielded in reverse order.

The pattern can be a simple `&str`, `char`, or a closure that determines the split. Additional libraries might provide more complex patterns like regular expressions.

Equivalent to `split`, except that the trailing substring is skipped if empty.

This method can be used for string data that is terminated, rather than separated by a pattern.

# Iterator behavior

The returned iterator requires that the pattern supports a reverse search, and it will be double ended if a forward/reverse search yields the same elements.

For iterating from the front, the `split_terminator` method can be used.

# Examples

    let v: Vec<&str> = "A.B.".rsplit_terminator('.').collect();
    assert_eq!(v, ["B", "A"]);

    let v: Vec<&str> = "A..B..".rsplit_terminator(".").collect();
    assert_eq!(v, ["", "B", "", "A"]);Run

#### `fn splitn<'a, P>(&'a self, n: usize, pat: P) -> SplitN<'a, P> where P: Pattern<'a>`

An iterator over substrings of the given string slice, separated by a pattern, restricted to returning at most `n` items.

If `n` substrings are returned, the last substring (the `n`th substring) will contain the remainder of the string.

The pattern can be a `&str`, `char`, or a closure that determines the split.

# Iterator behavior

The returned iterator will not be double ended, because it is not efficient to support.

If the pattern allows a reverse search, the `rsplitn` method can be used.

# Examples

Simple patterns:

    let v: Vec<&str> = "Mary had a little lambda".splitn(3, ' ').collect();
    assert_eq!(v, ["Mary", "had", "a little lambda"]);

    let v: Vec<&str> = "lionXXtigerXleopard".splitn(3, "X").collect();
    assert_eq!(v, ["lion", "", "tigerXleopard"]);

    let v: Vec<&str> = "abcXdef".splitn(1, 'X').collect();
    assert_eq!(v, ["abcXdef"]);

    let v: Vec<&str> = "".splitn(1, 'X').collect();
    assert_eq!(v, [""]);Run

A more complex pattern, using a closure:

    let v: Vec<&str> = "abc1defXghi".splitn(2, |c| c == '1' || c == 'X').collect();
    assert_eq!(v, ["abc", "defXghi"]);Run

#### `fn rsplitn<'a, P>(&'a self, n: usize, pat: P) -> RSplitN<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`

An iterator over substrings of this string slice, separated by a pattern, starting from the end of the string, restricted to returning at most `n` items.

If `n` substrings are returned, the last substring (the `n`th substring) will contain the remainder of the string.

The pattern can be a `&str`, `char`, or a closure that determines the split.

# Iterator behavior

The returned iterator will not be double ended, because it is not efficient to support.

For splitting from the front, the `splitn` method can be used.

# Examples

Simple patterns:

    let v: Vec<&str> = "Mary had a little lamb".rsplitn(3, ' ').collect();
    assert_eq!(v, ["lamb", "little", "Mary had a"]);

    let v: Vec<&str> = "lionXXtigerXleopard".rsplitn(3, 'X').collect();
    assert_eq!(v, ["leopard", "tiger", "lionX"]);

    let v: Vec<&str> = "lion::tiger::leopard".rsplitn(2, "::").collect();
    assert_eq!(v, ["leopard", "lion::tiger"]);Run

A more complex pattern, using a closure:

    let v: Vec<&str> = "abc1defXghi".rsplitn(2, |c| c == '1' || c == 'X').collect();
    assert_eq!(v, ["ghi", "abc1def"]);Run

#### `fn matches<'a, P>(&'a self, pat: P) -> Matches<'a, P> where P: Pattern<'a>`
1.2.0

An iterator over the matches of a pattern within the given string slice.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Iterator behavior

The returned iterator will be a `DoubleEndedIterator` if the pattern allows a reverse search and forward/reverse search yields the same elements. This is true for, eg, `char` but not for `&str`.

If the pattern allows a reverse search but its results might differ from a forward search, the `rmatches` method can be used.

# Examples

Basic usage:

    let v: Vec<&str> = "abcXXXabcYYYabc".matches("abc").collect();
    assert_eq!(v, ["abc", "abc", "abc"]);

    let v: Vec<&str> = "1abc2abc3".matches(char::is_numeric).collect();
    assert_eq!(v, ["1", "2", "3"]);Run

#### `fn rmatches<'a, P>(&'a self, pat: P) -> RMatches<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`
1.2.0

An iterator over the matches of a pattern within this string slice, yielded in reverse order.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Iterator behavior

The returned iterator requires that the pattern supports a reverse search, and it will be a `DoubleEndedIterator` if a forward/reverse search yields the same elements.

For iterating from the front, the `matches` method can be used.

# Examples

Basic usage:

    let v: Vec<&str> = "abcXXXabcYYYabc".rmatches("abc").collect();
    assert_eq!(v, ["abc", "abc", "abc"]);

    let v: Vec<&str> = "1abc2abc3".rmatches(char::is_numeric).collect();
    assert_eq!(v, ["3", "2", "1"]);Run

#### `fn match_indices<'a, P>(&'a self, pat: P) -> MatchIndices<'a, P> where P: Pattern<'a>`
1.5.0

An iterator over the disjoint matches of a pattern within this string slice as well as the index that the match starts at.

For matches of `pat` within `self` that overlap, only the indices corresponding to the first match are returned.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Iterator behavior

The returned iterator will be a `DoubleEndedIterator` if the pattern allows a reverse search and forward/reverse search yields the same elements. This is true for, eg, `char` but not for `&str`.

If the pattern allows a reverse search but its results might differ from a forward search, the `rmatch_indices` method can be used.

# Examples

Basic usage:

    let v: Vec<_> = "abcXXXabcYYYabc".match_indices("abc").collect();
    assert_eq!(v, [(0, "abc"), (6, "abc"), (12, "abc")]);

    let v: Vec<_> = "1abcabc2".match_indices("abc").collect();
    assert_eq!(v, [(1, "abc"), (4, "abc")]);

    let v: Vec<_> = "ababa".match_indices("aba").collect();
    assert_eq!(v, [(0, "aba")]); // only the first `aba`Run

#### `fn rmatch_indices<'a, P>(&'a self, pat: P) -> RMatchIndices<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`
1.5.0

An iterator over the disjoint matches of a pattern within `self`, yielded in reverse order along with the index of the match.

For matches of `pat` within `self` that overlap, only the indices corresponding to the last match are returned.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Iterator behavior

The returned iterator requires that the pattern supports a reverse search, and it will be a `DoubleEndedIterator` if a forward/reverse search yields the same elements.

For iterating from the front, the `match_indices` method can be used.

# Examples

Basic usage:

    let v: Vec<_> = "abcXXXabcYYYabc".rmatch_indices("abc").collect();
    assert_eq!(v, [(12, "abc"), (6, "abc"), (0, "abc")]);

    let v: Vec<_> = "1abcabc2".rmatch_indices("abc").collect();
    assert_eq!(v, [(4, "abc"), (1, "abc")]);

    let v: Vec<_> = "ababa".rmatch_indices("aba").collect();
    assert_eq!(v, [(2, "aba")]); // only the last `aba`Run

#### `fn trim(&self) -> &str`

Returns a string slice with leading and trailing whitespace removed.

'Whitespace' is defined according to the terms of the Unicode Derived Core Property `White_Space`.

# Examples

Basic usage:

    let s = " Hello\tworld\t";

    assert_eq!("Hello\tworld", s.trim());Run

#### `fn trim_left(&self) -> &str`

Returns a string slice with leading whitespace removed.

'Whitespace' is defined according to the terms of the Unicode Derived Core Property `White_Space`.

# Text directionality

A string is a sequence of bytes. 'Left' in this context means the first position of that byte string; for a language like Arabic or Hebrew which are 'right to left' rather than 'left to right', this will be the right side, not the left.

# Examples

Basic usage:

    let s = " Hello\tworld\t";

    assert_eq!("Hello\tworld\t", s.trim_left());Run

Directionality:

    let s = "  English";
    assert!(Some('E') == s.trim_left().chars().next());

    let s = "  עברית";
    assert!(Some('ע') == s.trim_left().chars().next());Run

#### `fn trim_right(&self) -> &str`

Returns a string slice with trailing whitespace removed.

'Whitespace' is defined according to the terms of the Unicode Derived Core Property `White_Space`.

# Text directionality

A string is a sequence of bytes. 'Right' in this context means the last position of that byte string; for a language like Arabic or Hebrew which are 'right to left' rather than 'left to right', this will be the left side, not the right.

# Examples

Basic usage:

    let s = " Hello\tworld\t";

    assert_eq!(" Hello\tworld", s.trim_right());Run

Directionality:

    let s = "English  ";
    assert!(Some('h') == s.trim_right().chars().rev().next());

    let s = "עברית  ";
    assert!(Some('ת') == s.trim_right().chars().rev().next());Run

#### `fn trim_matches<'a, P>(&'a self, pat: P) -> &'a str where P: Pattern<'a>, P::Searcher: DoubleEndedSearcher<'a>`

Returns a string slice with all prefixes and suffixes that match a pattern repeatedly removed.

The pattern can be a `char` or a closure that determines if a character matches.

# Examples

Simple patterns:

    assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar");
    assert_eq!("123foo1bar123".trim_matches(char::is_numeric), "foo1bar");

    let x: &[_] = &['1', '2'];
    assert_eq!("12foo1bar12".trim_matches(x), "foo1bar");Run

A more complex pattern, using a closure:

    assert_eq!("1foo1barXX".trim_matches(|c| c == '1' || c == 'X'), "foo1bar");Run

#### `fn trim_left_matches<'a, P>(&'a self, pat: P) -> &'a str where P: Pattern<'a>`

Returns a string slice with all prefixes that match a pattern repeatedly removed.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Text directionality

A string is a sequence of bytes. 'Left' in this context means the first position of that byte string; for a language like Arabic or Hebrew which are 'right to left' rather than 'left to right', this will be the right side, not the left.

# Examples

Basic usage:

    assert_eq!("11foo1bar11".trim_left_matches('1'), "foo1bar11");
    assert_eq!("123foo1bar123".trim_left_matches(char::is_numeric), "foo1bar123");

    let x: &[_] = &['1', '2'];
    assert_eq!("12foo1bar12".trim_left_matches(x), "foo1bar12");Run

#### `fn trim_right_matches<'a, P>(&'a self, pat: P) -> &'a str where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>`

Returns a string slice with all suffixes that match a pattern repeatedly removed.

The pattern can be a `&str`, `char`, or a closure that determines if a character matches.

# Text directionality

A string is a sequence of bytes. 'Right' in this context means the last position of that byte string; for a language like Arabic or Hebrew which are 'right to left' rather than 'left to right', this will be the left side, not the right.

# Examples

Simple patterns:

    assert_eq!("11foo1bar11".trim_right_matches('1'), "11foo1bar");
    assert_eq!("123foo1bar123".trim_right_matches(char::is_numeric), "123foo1bar");

    let x: &[_] = &['1', '2'];
    assert_eq!("12foo1bar12".trim_right_matches(x), "12foo1bar");Run

A more complex pattern, using a closure:

    assert_eq!("1fooX".trim_left_matches(|c| c == '1' || c == 'X'), "fooX");Run

#### `fn parse<F>(&self) -> Result<F, F::Err> where F: FromStr`

Parses this string slice into another type.

Because `parse()` is so general, it can cause problems with type inference. As such, `parse()` is one of the few times you'll see the syntax affectionately known as the 'turbofish': `::<>`. This helps the inference algorithm understand specifically which type you're trying to parse into.

`parse()` can parse any type that implements the `FromStr` trait.

# Errors

Will return `Err` if it's not possible to parse this string slice into the desired type.

# Example

Basic usage

    let four: u32 = "4".parse().unwrap();

    assert_eq!(4, four);Run

Using the 'turbofish' instead of annotating `four`:

    let four = "4".parse::<u32>();

    assert_eq!(Ok(4), four);Run

Failing to parse:

    let nope = "j".parse::<u32>();

    assert!(nope.is_err());Run

#### `fn replace<'a, P>(&'a self, from: P, to: &str) -> String where P: Pattern<'a>`

Replaces all matches of a pattern with another string.

`replace` creates a new `String`, and copies the data from this string slice into it. While doing so, it attempts to find matches of a pattern. If it finds any, it replaces them with the replacement string slice.

# Examples

Basic usage:

    let s = "this is old";

    assert_eq!("this is new", s.replace("old", "new"));Run

When the pattern doesn't match:

    let s = "this is old";
    assert_eq!(s, s.replace("cookie monster", "little lamb"));Run

#### `fn replacen<'a, P>(&'a self, pat: P, to: &str, count: usize) -> String where P: Pattern<'a>`
1.16.0

Replaces first N matches of a pattern with another string.

`replacen` creates a new `String`, and copies the data from this string slice into it. While doing so, it attempts to find matches of a pattern. If it finds any, it replaces them with the replacement string slice at most `N` times.

# Examples

Basic usage:

    let s = "foo foo 123 foo";
    assert_eq!("new new 123 foo", s.replacen("foo", "new", 2));
    assert_eq!("faa fao 123 foo", s.replacen('o', "a", 3));
    assert_eq!("foo foo new23 foo", s.replacen(char::is_numeric, "new", 1));Run

When the pattern doesn't match:

    let s = "this is old";
    assert_eq!(s, s.replacen("cookie monster", "little lamb", 10));Run

#### `fn to_lowercase(&self) -> String`
1.2.0

Returns the lowercase equivalent of this string slice, as a new `String`.

'Lowercase' is defined according to the terms of the Unicode Derived Core Property `Lowercase`.

Since some characters can expand into multiple characters when changing the case, this function returns a `String` instead of modifying the parameter in-place.

# Examples

Basic usage:

    let s = "HELLO";

    assert_eq!("hello", s.to_lowercase());Run

A tricky example, with sigma:

    let sigma = "Σ";

    assert_eq!("σ", sigma.to_lowercase());

    // but at the end of a word, it's ς, not σ:
    let odysseus = "ὈΔΥΣΣΕΎΣ";

    assert_eq!("ὀδυσσεύς", odysseus.to_lowercase());Run

Languages without case are not changed:

    let new_year = "农历新年";

    assert_eq!(new_year, new_year.to_lowercase());Run

#### `fn to_uppercase(&self) -> String`
1.2.0

Returns the uppercase equivalent of this string slice, as a new `String`.

'Uppercase' is defined according to the terms of the Unicode Derived Core Property `Uppercase`.

Since some characters can expand into multiple characters when changing the case, this function returns a `String` instead of modifying the parameter in-place.

# Examples

Basic usage:

    let s = "hello";

    assert_eq!("HELLO", s.to_uppercase());Run

Scripts without case are not changed:

    let new_year = "农历新年";

    assert_eq!(new_year, new_year.to_uppercase());Run

#### `fn escape_debug(&self) -> String`

🔬 This is a nightly-only experimental API. (`str_escape` #27791)

return type may change to be an iterator

Escapes each char in `s` with `char::escape_debug`.

#### `fn escape_default(&self) -> String`

🔬 This is a nightly-only experimental API. (`str_escape` #27791)

return type may change to be an iterator

Escapes each char in `s` with `char::escape_default`.

#### `fn escape_unicode(&self) -> String`

🔬 This is a nightly-only experimental API. (`str_escape` #27791)

return type may change to be an iterator

Escapes each char in `s` with `char::escape_unicode`.

#### `fn into_string(self: Box<str>) -> String`
1.4.0

Converts a `Box<str>` into a `String` without copying or allocating.

# Examples

Basic usage:

    let string = String::from("birthday gift");
    let boxed_str = string.clone().into_boxed_str();

    assert_eq!(boxed_str.into_string(), string);Run

#### `fn repeat(&self, n: usize) -> String`
1.16.0

Create a `String` by repeating a string `n` times.

# Examples

Basic usage:

    assert_eq!("abc".repeat(4), String::from("abcabcabcabc"));Run

## Trait Implementations

### `impl ToString for str`
1.9.0
[src]

#### `fn to_string(&self) -> String`

Converts the given value to a `String`. Read more

### `impl ToOwned for str`
[src]

#### `type Owned = String`

#### `fn to_owned(&self) -> String`

Creates owned data from borrowed data, usually by cloning. Read more

### `impl<'a, 'b> PartialEq<String> for str`
[src]

#### `fn eq(&self, other: &String) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &String) -> bool`

This method tests for `!=`.

### `impl<'a, 'b> PartialEq<String> for &'a str`
[src]

#### `fn eq(&self, other: &String) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &String) -> bool`

This method tests for `!=`.

### `impl<'a, 'b> PartialEq<Cow<'a, str>> for str`
[src]

#### `fn eq(&self, other: &Cow<'a, str>) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &Cow<'a, str>) -> bool`

This method tests for `!=`.

### `impl<'a, 'b> PartialEq<Cow<'a, str>> for &'b str`
[src]

#### `fn eq(&self, other: &Cow<'a, str>) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &Cow<'a, str>) -> bool`

This method tests for `!=`.

### `impl Ord for str`
[src]

Implements ordering of strings.

Strings are ordered lexicographically by their byte values. This orders Unicode code points based on their positions in the code charts. This is not necessarily the same as "alphabetical" order, which varies by language and locale. Sorting strings according to culturally-accepted standards requires locale-specific data that is outside the scope of the `str` type.

#### `fn cmp(&self, other: &str) -> Ordering`

This method returns an `Ordering` between `self` and `other`. Read more

### `impl Display for str`
[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter. Read more

### `impl Hash for str`
[src]

#### `fn hash<H>(&self, state: &mut H) where H: Hasher`

Feeds this value into the state given, updating the hasher as necessary.

#### `fn hash_slice<H>(data: &[Self], state: &mut H) where H: Hasher`
1.3.0

Feeds a slice of this type into the state provided.

### `impl PartialEq<str> for str`
[src]

#### `fn eq(&self, other: &str) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &str) -> bool`

This method tests for `!=`.

### `impl IndexMut<Range<usize>> for str`
1.2.0
[src]

Implements mutable substring slicing with syntax `&mut self[begin .. end]`.

Returns a mutable slice of the given string from the byte range [`begin`..`end`).

This operation is `O(1)`.

# Panics

Panics if `begin` or `end` does not point to the starting byte offset of a character (as defined by `is_char_boundary`). Requires that `begin <= end` and `end <= len` where `len` is the length of the string.

#### `fn index_mut(&mut self, index: Range<usize>) -> &mut str`

The method for the mutable indexing (`container[index]`) operation

### `impl IndexMut<RangeTo<usize>> for str`
1.2.0
[src]

Implements mutable substring slicing with syntax `&mut self[.. end]`.

Returns a mutable slice of the string from the beginning to byte offset `end`.

Equivalent to `&mut self[0 .. end]`.

#### `fn index_mut(&mut self, index: RangeTo<usize>) -> &mut str`

The method for the mutable indexing (`container[index]`) operation

### `impl IndexMut<RangeFrom<usize>> for str`
1.2.0
[src]

Implements mutable substring slicing with syntax `&mut self[begin ..]`.

Returns a mutable slice of the string from byte offset `begin` to the end of the string.

Equivalent to `&mut self[begin .. len]`.

#### `fn index_mut(&mut self, index: RangeFrom<usize>) -> &mut str`

The method for the mutable indexing (`container[index]`) operation

### `impl IndexMut<RangeFull> for str`
1.2.0
[src]

Implements mutable substring slicing with syntax `&mut self[..]`.

Returns a mutable slice of the whole string. This operation can never panic.

Equivalent to `&mut self[0 .. len]`.

#### `fn index_mut(&mut self, _index: RangeFull) -> &mut str`

The method for the mutable indexing (`container[index]`) operation

### `impl IndexMut<RangeInclusive<usize>> for str`
[src]

#### `fn index_mut(&mut self, index: RangeInclusive<usize>) -> &mut str`

The method for the mutable indexing (`container[index]`) operation

### `impl IndexMut<RangeToInclusive<usize>> for str`
[src]

#### `fn index_mut(&mut self, index: RangeToInclusive<usize>) -> &mut str`

The method for the mutable indexing (`container[index]`) operation

### `impl PartialOrd<str> for str`
[src]

Implements comparison operations on strings.

Strings are compared lexicographically by their byte values. This compares Unicode code points based on their positions in the code charts. This is not necessarily the same as "alphabetical" order, which varies by language and locale. Comparing strings according to culturally-accepted standards requires locale-specific data that is outside the scope of the `str` type.

#### `fn partial_cmp(&self, other: &str) -> Option<Ordering>`

This method returns an ordering between `self` and `other` values if one exists. Read more

#### `fn lt(&self, other: &Rhs) -> bool`

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more

#### `fn le(&self, other: &Rhs) -> bool`

This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more

#### `fn gt(&self, other: &Rhs) -> bool`

This method tests greater than (for `self` and `other`) and is used by the `>` operator. Read more

#### `fn ge(&self, other: &Rhs) -> bool`

This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more

### `impl<'a, 'b> Pattern<'a> for &'b str`
[src]

Non-allocating substring search.

Will handle the pattern `""` as returning empty matches at each character boundary.

#### `type Searcher = StrSearcher<'a, 'b>`

🔬 This is a nightly-only experimental API. (`pattern` #27721)

API not fully fleshed out and ready to be stabilized

Associated searcher for this pattern

#### `fn into_searcher(self, haystack: &'a str) -> StrSearcher<'a, 'b>`

🔬 This is a nightly-only experimental API. (`pattern` #27721)

API not fully fleshed out and ready to be stabilized

Constructs the associated searcher from `self` and the `haystack` to search in. Read more

#### `fn is_prefix_of(self, haystack: &'a str) -> bool`

🔬 This is a nightly-only experimental API. (`pattern` #27721)

API not fully fleshed out and ready to be stabilized

Checks whether the pattern matches at the front of the haystack

#### `fn is_suffix_of(self, haystack: &'a str) -> bool`

🔬 This is a nightly-only experimental API. (`pattern` #27721)

API not fully fleshed out and ready to be stabilized

Checks whether the pattern matches at the back of the haystack

#### `fn is_contained_in(self, haystack: &'a str) -> bool`

🔬 This is a nightly-only experimental API. (`pattern` #27721)

API not fully fleshed out and ready to be stabilized

Checks whether the pattern matches anywhere in the haystack

### `impl AsRef<str> for str`
[src]

#### `fn as_ref(&self) -> &str`

Performs the conversion.

### `impl AsRef<[u8]> for str`
[src]

#### `fn as_ref(&self) -> &[u8]`

Performs the conversion.

### `impl Eq for str`
[src]

### `impl<'a> Default for &'a str`
[src]

#### `fn default() -> &'a str`

Creates an empty str

### `impl Index<Range<usize>> for str`
[src]

Implements substring slicing with syntax `&self[begin .. end]`.

Returns a slice of the given string from the byte range [`begin`..`end`).

This operation is `O(1)`.

# Panics

Panics if `begin` or `end` does not point to the starting byte offset of a character (as defined by `is_char_boundary`). Requires that `begin <= end` and `end <= len` where `len` is the length of the string.

# Examples

    let s = "Löwe 老虎 Léopard";
    assert_eq!(&s[0 .. 1], "L");

    assert_eq!(&s[1 .. 9], "öwe 老");

    // these will panic:
    // byte 2 lies within `ö`:
    // &s[2 ..3];

    // byte 8 lies within `老`
    // &s[1 .. 8];

    // byte 100 is outside the string
    // &s[3 .. 100];Run

#### `type Output = str`

The returned type after indexing

#### `fn index(&self, index: Range<usize>) -> &str`

The method for the indexing (`container[index]`) operation

### `impl Index<RangeTo<usize>> for str`
[src]

Implements substring slicing with syntax `&self[.. end]`.

Returns a slice of the string from the beginning to byte offset `end`.

Equivalent to `&self[0 .. end]`.

#### `type Output = str`

The returned type after indexing

#### `fn index(&self, index: RangeTo<usize>) -> &str`

The method for the indexing (`container[index]`) operation

### `impl Index<RangeFrom<usize>> for str`
[src]

Implements substring slicing with syntax `&self[begin ..]`.

Returns a slice of the string from byte offset `begin` to the end of the string.

Equivalent to `&self[begin .. len]`.

#### `type Output = str`

The returned type after indexing

#### `fn index(&self, index: RangeFrom<usize>) -> &str`

The method for the indexing (`container[index]`) operation

### `impl Index<RangeFull> for str`
[src]

Implements substring slicing with syntax `&self[..]`.

Returns a slice of the whole string. This operation can never panic.

Equivalent to `&self[0 .. len]`.

#### `type Output = str`

The returned type after indexing

#### `fn index(&self, _index: RangeFull) -> &str`

The method for the indexing (`container[index]`) operation

### `impl Index<RangeInclusive<usize>> for str`
[src]

#### `type Output = str`

The returned type after indexing

#### `fn index(&self, index: RangeInclusive<usize>) -> &str`

The method for the indexing (`container[index]`) operation

### `impl Index<RangeToInclusive<usize>> for str`
[src]

#### `type Output = str`

The returned type after indexing

#### `fn index(&self, index: RangeToInclusive<usize>) -> &str`

The method for the indexing (`container[index]`) operation

### `impl Debug for str`
[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter.

### `impl UnicodeStr for str`
[src]

#### `fn split_whitespace(&self) -> SplitWhitespace`

🔬 This is a nightly-only experimental API. (`unicode` #27783)

#### `fn is_whitespace(&self) -> bool`

🔬 This is a nightly-only experimental API. (`unicode` #27783)

#### `fn is_alphanumeric(&self) -> bool`

🔬 This is a nightly-only experimental API. (`unicode` #27783)

#### `fn trim(&self) -> &str`

🔬 This is a nightly-only experimental API. (`unicode` #27783)

#### `fn trim_left(&self) -> &str`

🔬 This is a nightly-only experimental API. (`unicode` #27783)

#### `fn trim_right(&self) -> &str`

🔬 This is a nightly-only experimental API. (`unicode` #27783)

### `impl AsciiExt for str`
[src]

#### `type Owned = String`

Container type for copied ASCII characters.

#### `fn is_ascii(&self) -> bool`

Checks if the value is within the ASCII range. Read more

#### `fn to_ascii_uppercase(&self) -> String`

Makes a copy of the value in its ASCII upper case equivalent. Read more

#### `fn to_ascii_lowercase(&self) -> String`

Makes a copy of the value in its ASCII lower case equivalent. Read more

#### `fn eq_ignore_ascii_case(&self, other: &str) -> bool`

Checks that two values are an ASCII case-insensitive match. Read more

#### `fn make_ascii_uppercase(&mut self)`

Converts this type to its ASCII upper case equivalent in-place. Read more

#### `fn make_ascii_lowercase(&mut self)`

Converts this type to its ASCII lower case equivalent in-place. Read more

#### `fn is_ascii_alphabetic(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII alphabetic character: U+0041 'A' ... U+005A 'Z' or U+0061 'a' ... U+007A 'z'. For strings, true if all characters in the string are ASCII alphabetic. Read more

#### `fn is_ascii_uppercase(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII uppercase character: U+0041 'A' ... U+005A 'Z'. For strings, true if all characters in the string are ASCII uppercase. Read more

#### `fn is_ascii_lowercase(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII lowercase character: U+0061 'a' ... U+007A 'z'. For strings, true if all characters in the string are ASCII lowercase. Read more

#### `fn is_ascii_alphanumeric(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII alphanumeric character: U+0041 'A' ... U+005A 'Z', U+0061 'a' ... U+007A 'z', or U+0030 '0' ... U+0039 '9'. For strings, true if all characters in the string are ASCII alphanumeric. Read more

#### `fn is_ascii_digit(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII decimal digit: U+0030 '0' ... U+0039 '9'. For strings, true if all characters in the string are ASCII digits. Read more

#### `fn is_ascii_hexdigit(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII hexadecimal digit: U+0030 '0' ... U+0039 '9', U+0041 'A' ... U+0046 'F', or U+0061 'a' ... U+0066 'f'. For strings, true if all characters in the string are ASCII hex digits. Read more

#### `fn is_ascii_punctuation(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII punctuation character: U+0021 ... U+002F `! " # $ % & ' ( ) * + , - . /` U+003A ... U+0040 `: ; < = > ? @` U+005B ... U+0060 `[ \\ ] ^ _ \`` U+007B ... U+007E`{ | } ~` For strings, true if all characters in the string are ASCII punctuation. Read more

#### `fn is_ascii_graphic(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII graphic character: U+0021 '@' ... U+007E '~'. For strings, true if all characters in the string are ASCII punctuation. Read more

#### `fn is_ascii_whitespace(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII whitespace character: U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED, U+000C FORM FEED, or U+000D CARRIAGE RETURN. For strings, true if all characters in the string are ASCII whitespace. Read more

#### `fn is_ascii_control(&self) -> bool`

🔬 This is a nightly-only experimental API. (`ascii_ctype` #39658)

Checks if the value is an ASCII control character: U+0000 NUL ... U+001F UNIT SEPARATOR, or U+007F DELETE. Note that most ASCII whitespace characters are control characters, but SPACE is not. Read more

### `impl PartialEq<OsString> for str`
[src]

#### `fn eq(&self, other: &OsString) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &Rhs) -> bool`

This method tests for `!=`.

### `impl PartialEq<OsStr> for str`
[src]

#### `fn eq(&self, other: &OsStr) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &Rhs) -> bool`

This method tests for `!=`.

### `impl AsRef<OsStr> for str`
[src]

#### `fn as_ref(&self) -> &OsStr`

Performs the conversion.

### `impl ToSocketAddrs for str`
[src]

#### `type Iter = IntoIter<SocketAddr>`

Returned iterator over socket addresses which this type may correspond to. Read more

#### `fn to_socket_addrs(&self) -> Result<IntoIter<SocketAddr>>`

Converts this object to an iterator of resolved `SocketAddr`s. Read more

### `impl AsRef<Path> for str`
[src]

#### `fn as_ref(&self) -> &Path`

Performs the conversion.

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