Struct std::string::StringStable [-]  [+] [src]

pub struct String {
    // some fields omitted
}

A growable string stored as a UTF-8 encoded buffer.

Methods

impl String

fn new() -> String

Creates a new string buffer initialized with the empty string.

Examples

fn main() { let mut s = String::new(); }
let mut s = String::new();

fn with_capacity(capacity: uint) -> String

Creates a new string buffer with the given capacity. The string will be able to hold exactly capacity bytes without reallocating. If capacity is 0, the string will not allocate.

Examples

fn main() { let mut s = String::with_capacity(10); }
let mut s = String::with_capacity(10);

fn from_str(string: &str) -> String

Creates a new string buffer from the given string.

Examples

fn main() { let s = String::from_str("hello"); assert_eq!(s.as_slice(), "hello"); }
let s = String::from_str("hello");
assert_eq!(s.as_slice(), "hello");

fn from_utf8(vec: Vec<u8>) -> Result<String, FromUtf8Error>

Returns the vector as a string buffer, if possible, taking care not to copy it.

Failure

If the given vector is not valid UTF-8, then the original vector and the corresponding error is returned.

Examples

fn main() { #![allow(deprecated)] use std::str::Utf8Error; let hello_vec = vec![104, 101, 108, 108, 111]; let s = String::from_utf8(hello_vec).unwrap(); assert_eq!(s, "hello"); let invalid_vec = vec![240, 144, 128]; let s = String::from_utf8(invalid_vec).err().unwrap(); assert_eq!(s.utf8_error(), Utf8Error::TooShort); assert_eq!(s.into_bytes(), vec![240, 144, 128]); }
use std::str::Utf8Error;

let hello_vec = vec![104, 101, 108, 108, 111];
let s = String::from_utf8(hello_vec).unwrap();
assert_eq!(s, "hello");

let invalid_vec = vec![240, 144, 128];
let s = String::from_utf8(invalid_vec).err().unwrap();
assert_eq!(s.utf8_error(), Utf8Error::TooShort);
assert_eq!(s.into_bytes(), vec![240, 144, 128]);

fn from_utf8_lossy(v: &'a [u8]) -> Cow<'a, String, str>

Converts a vector of bytes to a new UTF-8 string. Any invalid UTF-8 sequences are replaced with U+FFFD REPLACEMENT CHARACTER.

Examples

fn main() { let input = b"Hello \xF0\x90\x80World"; let output = String::from_utf8_lossy(input); assert_eq!(output.as_slice(), "Hello \u{FFFD}World"); }
let input = b"Hello \xF0\x90\x80World";
let output = String::from_utf8_lossy(input);
assert_eq!(output.as_slice(), "Hello \u{FFFD}World");

fn from_utf16(v: &[u16]) -> Result<String, FromUtf16Error>

Decode a UTF-16 encoded vector v into a String, returning None if v contains any invalid data.

Examples

fn main() { // 𝄞music let mut v = &mut [0xD834, 0xDD1E, 0x006d, 0x0075, 0x0073, 0x0069, 0x0063]; assert_eq!(String::from_utf16(v).unwrap(), "𝄞music".to_string()); // 𝄞mu<invalid>ic v[4] = 0xD800; assert!(String::from_utf16(v).is_err()); }
// 𝄞music
let mut v = &mut [0xD834, 0xDD1E, 0x006d, 0x0075,
                  0x0073, 0x0069, 0x0063];
assert_eq!(String::from_utf16(v).unwrap(),
           "𝄞music".to_string());

// 𝄞mu<invalid>ic
v[4] = 0xD800;
assert!(String::from_utf16(v).is_err());

fn from_utf16_lossy(v: &[u16]) -> String

Decode a UTF-16 encoded vector v into a string, replacing invalid data with the replacement character (U+FFFD).

Examples

fn main() { // 𝄞mus<invalid>ic<invalid> let v = &[0xD834, 0xDD1E, 0x006d, 0x0075, 0x0073, 0xDD1E, 0x0069, 0x0063, 0xD834]; assert_eq!(String::from_utf16_lossy(v), "𝄞mus\u{FFFD}ic\u{FFFD}".to_string()); }
// 𝄞mus<invalid>ic<invalid>
let v = &[0xD834, 0xDD1E, 0x006d, 0x0075,
          0x0073, 0xDD1E, 0x0069, 0x0063,
          0xD834];

assert_eq!(String::from_utf16_lossy(v),
           "𝄞mus\u{FFFD}ic\u{FFFD}".to_string());

fn from_chars(chs: &[char]) -> String

Convert a vector of chars to a String.

Examples

fn main() { #![allow(deprecated)] let chars = &['h', 'e', 'l', 'l', 'o']; let s = String::from_chars(chars); assert_eq!(s.as_slice(), "hello"); }
let chars = &['h', 'e', 'l', 'l', 'o'];
let s = String::from_chars(chars);
assert_eq!(s.as_slice(), "hello");

unsafe fn from_raw_parts(buf: *mut u8, length: uint, capacity: uint) -> String

Creates a new String from a length, capacity, and pointer.

This is unsafe because: * We call Vec::from_raw_parts to get a Vec<u8>; * We assume that the Vec contains valid UTF-8.

unsafe fn from_raw_buf(buf: *const u8) -> String

Creates a String from a null-terminated *const u8 buffer.

This function is unsafe because we dereference memory until we find the NUL character, which is not guaranteed to be present. Additionally, the slice is not checked to see whether it contains valid UTF-8

unsafe fn from_raw_buf_len(buf: *const u8, len: uint) -> String

Creates a String from a *const u8 buffer of the given length.

This function is unsafe because it blindly assumes the validity of the pointer buf for len bytes of memory. This function will copy the memory from buf into a new allocation (owned by the returned String).

This function is also unsafe because it does not validate that the buffer is valid UTF-8 encoded data.

unsafe fn from_utf8_unchecked(bytes: Vec<u8>) -> String

Converts a vector of bytes to a new String without checking if it contains valid UTF-8. This is unsafe because it assumes that the UTF-8-ness of the vector has already been validated.

fn into_bytes(self) -> Vec<u8>

Return the underlying byte buffer, encoded as UTF-8.

Examples

fn main() { let s = String::from_str("hello"); let bytes = s.into_bytes(); assert_eq!(bytes, vec![104, 101, 108, 108, 111]); }
let s = String::from_str("hello");
let bytes = s.into_bytes();
assert_eq!(bytes, vec![104, 101, 108, 108, 111]);

fn from_char(length: uint, ch: char) -> String

Creates a string buffer by repeating a character length times.

Examples

fn main() { #![allow(deprecated)] let s = String::from_char(5, 'a'); assert_eq!(s.as_slice(), "aaaaa"); }
let s = String::from_char(5, 'a');
assert_eq!(s.as_slice(), "aaaaa");

fn push_str(&mut self, string: &str)

Pushes the given string onto this string buffer.

Examples

fn main() { let mut s = String::from_str("foo"); s.push_str("bar"); assert_eq!(s.as_slice(), "foobar"); }
let mut s = String::from_str("foo");
s.push_str("bar");
assert_eq!(s.as_slice(), "foobar");

fn grow(&mut self, count: uint, ch: char)

Pushes ch onto the given string count times.

Examples

fn main() { #![allow(deprecated)] let mut s = String::from_str("foo"); s.grow(5, 'Z'); assert_eq!(s.as_slice(), "fooZZZZZ"); }
let mut s = String::from_str("foo");
s.grow(5, 'Z');
assert_eq!(s.as_slice(), "fooZZZZZ");

fn capacity(&self) -> uint

Returns the number of bytes that this string buffer can hold without reallocating.

Examples

fn main() { let s = String::with_capacity(10); assert!(s.capacity() >= 10); }
let s = String::with_capacity(10);
assert!(s.capacity() >= 10);

fn reserve_additional(&mut self, extra: uint)

Deprecated: Renamed to reserve.

fn reserve(&mut self, additional: uint)

Reserves capacity for at least additional more bytes to be inserted in the given String. The collection may reserve more space to avoid frequent reallocations.

Panics

Panics if the new capacity overflows uint.

Examples

fn main() { let mut s = String::new(); s.reserve(10); assert!(s.capacity() >= 10); }
let mut s = String::new();
s.reserve(10);
assert!(s.capacity() >= 10);

fn reserve_exact(&mut self, additional: uint)

Reserves the minimum capacity for exactly additional more bytes to be inserted in the given String. Does nothing if the capacity is already sufficient.

Note that the allocator may give the collection more space than it requests. Therefore capacity can not be relied upon to be precisely minimal. Prefer reserve if future insertions are expected.

Panics

Panics if the new capacity overflows uint.

Examples

fn main() { let mut s = String::new(); s.reserve(10); assert!(s.capacity() >= 10); }
let mut s = String::new();
s.reserve(10);
assert!(s.capacity() >= 10);

fn shrink_to_fit(&mut self)

Shrinks the capacity of this string buffer to match its length.

Examples

fn main() { let mut s = String::from_str("foo"); s.reserve(100); assert!(s.capacity() >= 100); s.shrink_to_fit(); assert_eq!(s.capacity(), 3); }
let mut s = String::from_str("foo");
s.reserve(100);
assert!(s.capacity() >= 100);
s.shrink_to_fit();
assert_eq!(s.capacity(), 3);

fn push(&mut self, ch: char)

Adds the given character to the end of the string.

Examples

fn main() { let mut s = String::from_str("abc"); s.push('1'); s.push('2'); s.push('3'); assert_eq!(s.as_slice(), "abc123"); }
let mut s = String::from_str("abc");
s.push('1');
s.push('2');
s.push('3');
assert_eq!(s.as_slice(), "abc123");

fn as_bytes(&'a self) -> &'a [u8]

Works with the underlying buffer as a byte slice.

Examples

fn main() { let s = String::from_str("hello"); let b: &[_] = &[104, 101, 108, 108, 111]; assert_eq!(s.as_bytes(), b); }
let s = String::from_str("hello");
let b: &[_] = &[104, 101, 108, 108, 111];
assert_eq!(s.as_bytes(), b);

fn truncate(&mut self, new_len: uint)

Shortens a string to the specified length.

Panics

Panics if new_len > current length, or if new_len is not a character boundary.

Examples

fn main() { let mut s = String::from_str("hello"); s.truncate(2); assert_eq!(s.as_slice(), "he"); }
let mut s = String::from_str("hello");
s.truncate(2);
assert_eq!(s.as_slice(), "he");

fn pop(&mut self) -> Option<char>

Removes the last character from the string buffer and returns it. Returns None if this string buffer is empty.

Examples

fn main() { let mut s = String::from_str("foo"); assert_eq!(s.pop(), Some('o')); assert_eq!(s.pop(), Some('o')); assert_eq!(s.pop(), Some('f')); assert_eq!(s.pop(), None); }
let mut s = String::from_str("foo");
assert_eq!(s.pop(), Some('o'));
assert_eq!(s.pop(), Some('o'));
assert_eq!(s.pop(), Some('f'));
assert_eq!(s.pop(), None);

fn remove(&mut self, idx: uint) -> char

Removes the character from the string buffer at byte position idx and returns it.

Warning

This is an O(n) operation as it requires copying every element in the buffer.

Panics

If idx does not lie on a character boundary, or if it is out of bounds, then this function will panic.

Examples

fn main() { let mut s = String::from_str("foo"); assert_eq!(s.remove(0), 'f'); assert_eq!(s.remove(1), 'o'); assert_eq!(s.remove(0), 'o'); }
let mut s = String::from_str("foo");
assert_eq!(s.remove(0), 'f');
assert_eq!(s.remove(1), 'o');
assert_eq!(s.remove(0), 'o');

fn insert(&mut self, idx: uint, ch: char)

Insert a character into the string buffer at byte position idx.

Warning

This is an O(n) operation as it requires copying every element in the buffer.

Panics

If idx does not lie on a character boundary or is out of bounds, then this function will panic.

unsafe fn as_mut_vec(&'a mut self) -> &'a mut Vec<u8>

Views the string buffer as a mutable sequence of bytes.

This is unsafe because it does not check to ensure that the resulting string will be valid UTF-8.

Examples

fn main() { let mut s = String::from_str("hello"); unsafe { let vec = s.as_mut_vec(); assert!(vec == &mut vec![104, 101, 108, 108, 111]); vec.reverse(); } assert_eq!(s.as_slice(), "olleh"); }
let mut s = String::from_str("hello");
unsafe {
    let vec = s.as_mut_vec();
    assert!(vec == &mut vec![104, 101, 108, 108, 111]);
    vec.reverse();
}
assert_eq!(s.as_slice(), "olleh");

fn len(&self) -> uint

Return the number of bytes in this string.

Examples

fn main() { let a = "foo".to_string(); assert_eq!(a.len(), 3); }
let a = "foo".to_string();
assert_eq!(a.len(), 3);

fn is_empty(&self) -> bool

Returns true if the string contains no bytes

Examples

fn main() { let mut v = String::new(); assert!(v.is_empty()); v.push('a'); assert!(!v.is_empty()); }
let mut v = String::new();
assert!(v.is_empty());
v.push('a');
assert!(!v.is_empty());

fn clear(&mut self)

Truncates the string, returning it to 0 length.

Examples

fn main() { let mut s = "foo".to_string(); s.clear(); assert!(s.is_empty()); }
let mut s = "foo".to_string();
s.clear();
assert!(s.is_empty());

Trait Implementations

impl OwnedAsciiExt for String

fn into_ascii_uppercase(self) -> String

fn into_ascii_lowercase(self) -> String

impl ToCStr for String

fn to_c_str(&self) -> CString

unsafe fn to_c_str_unchecked(&self) -> CString

fn with_c_str<T, F>(&self, f: F) -> T where F: FnOnce(*const c_char) -> T

unsafe fn with_c_str_unchecked<T, F>(&self, f: F) -> T where F: FnOnce(*const c_char) -> T

impl BytesContainer for String

fn container_as_bytes(&self) -> &[u8]

fn container_as_str(&self) -> Option<&str>

fn is_str(_: Option<&String>) -> bool

impl<'a> IntoMaybeOwned<'a> for String

fn into_maybe_owned(self) -> MaybeOwned<'a>

Examples

fn main() { let owned_string = String::from_str("orange"); let maybe_owned_string = owned_string.into_maybe_owned(); assert_eq!(true, maybe_owned_string.is_owned()); }
let owned_string = String::from_str("orange");
let maybe_owned_string = owned_string.into_maybe_owned();
assert_eq!(true, maybe_owned_string.is_owned());

impl FromIterator<char> for String

fn from_iter<I: Iterator<char>>(iterator: I) -> String

impl<'a> FromIterator<&'a str> for String

fn from_iter<I: Iterator<&'a str>>(iterator: I) -> String

impl Extend<char> for String

fn extend<I: Iterator<char>>(&mut self, iterator: I)

impl<'a> Extend<&'a str> for String

fn extend<I: Iterator<&'a str>>(&mut self, iterator: I)

impl PartialEq<String> for String

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

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

fn ne(&self, &String) -> bool

impl<'a> PartialEq<&'a str> for String

fn eq(&self, other: &&'a str) -> bool

fn ne(&self, other: &&'a str) -> bool

fn ne(&self, &&'a str) -> bool

impl<'a> PartialEq<Cow<'a, String, str>> for String

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

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

fn ne(&self, &Cow<'a, String, str>) -> bool

impl Str for String

fn as_slice(&'a self) -> &'a str

impl Default for String

fn default() -> String

impl Show for String

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

impl<H: Writer> Hash<H> for String

fn hash(&self, hasher: &mut H)

impl<'a, S: Str> Equiv<S> for String

fn equiv(&self, other: &S) -> bool

impl<'a> Add<&'a str, String> for String

fn add(self, other: &str) -> String

impl Slice<uint, str> for String

fn as_slice_(&'a self) -> &'a str

fn slice_from_or_fail(&'a self, from: &uint) -> &'a str

fn slice_to_or_fail(&'a self, to: &uint) -> &'a str

fn slice_or_fail(&'a self, from: &uint, to: &uint) -> &'a str

impl Deref<str> for String

fn deref(&'a self) -> &'a str

impl FromStr for String

fn from_str(s: &str) -> Option<String>

impl IntoCow<'static, String, str> for String

fn into_cow(self) -> Cow<'static, String, str>

Derived Implementations

impl Ord for String

fn cmp(&self, __arg_0: &String) -> Ordering

impl Eq for String

fn assert_receiver_is_total_eq(&self)

impl PartialOrd<String> for String

fn partial_cmp(&self, __arg_0: &String) -> Option<Ordering>

fn lt(&self, __arg_0: &String) -> bool

fn le(&self, __arg_0: &String) -> bool

fn gt(&self, __arg_0: &String) -> bool

fn ge(&self, __arg_0: &String) -> bool

fn lt(&self, &String) -> bool

fn le(&self, &String) -> bool

fn gt(&self, &String) -> bool

fn ge(&self, &String) -> bool

impl Clone for String

fn clone(&self) -> String

fn clone_from(&mut self, &String)