Struct ruststep::ap201::explicit_draughting::Identifier[][src]

pub struct Identifier(pub String);

Tuple Fields

0: String

Methods from Deref<Target = String>

Extracts a string slice containing the entire String.

Examples

Basic usage:

let s = String::from("foo");

assert_eq!("foo", s.as_str());

Converts a String into a mutable string slice.

Examples

Basic usage:

let mut s = String::from("foobar");
let s_mut_str = s.as_mut_str();

s_mut_str.make_ascii_uppercase();

assert_eq!("FOOBAR", s_mut_str);

Appends a given string slice onto the end of this String.

Examples

Basic usage:

let mut s = String::from("foo");

s.push_str("bar");

assert_eq!("foobar", s);
🔬 This is a nightly-only experimental API. (string_extend_from_within)

Copies elements from src range to the end of the string.

Panics

Panics if the starting point or end point do not lie on a char boundary, or if they’re out of bounds.

Examples

#![feature(string_extend_from_within)]
let mut string = String::from("abcde");

string.extend_from_within(2..);
assert_eq!(string, "abcdecde");

string.extend_from_within(..2);
assert_eq!(string, "abcdecdeab");

string.extend_from_within(4..8);
assert_eq!(string, "abcdecdeabecde");

Returns this String’s capacity, in bytes.

Examples

Basic usage:

let s = String::with_capacity(10);

assert!(s.capacity() >= 10);

Ensures that this String’s capacity is at least additional bytes larger than its length.

The capacity may be increased by more than additional bytes if it chooses, to prevent frequent reallocations.

If you do not want this “at least” behavior, see the reserve_exact method.

Panics

Panics if the new capacity overflows usize.

Examples

Basic usage:

let mut s = String::new();

s.reserve(10);

assert!(s.capacity() >= 10);

This might not actually increase the capacity:

let mut s = String::with_capacity(10);
s.push('a');
s.push('b');

// s now has a length of 2 and a capacity of 10
assert_eq!(2, s.len());
assert_eq!(10, s.capacity());

// Since we already have an extra 8 capacity, calling this...
s.reserve(8);

// ... doesn't actually increase.
assert_eq!(10, s.capacity());

Ensures that this String’s capacity is additional bytes larger than its length.

Consider using the reserve method unless you absolutely know better than the allocator.

Panics

Panics if the new capacity overflows usize.

Examples

Basic usage:

let mut s = String::new();

s.reserve_exact(10);

assert!(s.capacity() >= 10);

This might not actually increase the capacity:

let mut s = String::with_capacity(10);
s.push('a');
s.push('b');

// s now has a length of 2 and a capacity of 10
assert_eq!(2, s.len());
assert_eq!(10, s.capacity());

// Since we already have an extra 8 capacity, calling this...
s.reserve_exact(8);

// ... doesn't actually increase.
assert_eq!(10, s.capacity());
🔬 This is a nightly-only experimental API. (try_reserve)

new API

Tries to reserve capacity for at least additional more elements to be inserted in the given String. The collection may reserve more space to avoid frequent reallocations. After calling reserve, capacity will be greater than or equal to self.len() + additional. Does nothing if capacity is already sufficient.

Errors

If the capacity overflows, or the allocator reports a failure, then an error is returned.

Examples

#![feature(try_reserve)]
use std::collections::TryReserveError;

fn process_data(data: &str) -> Result<String, TryReserveError> {
    let mut output = String::new();

    // Pre-reserve the memory, exiting if we can't
    output.try_reserve(data.len())?;

    // Now we know this can't OOM in the middle of our complex work
    output.push_str(data);

    Ok(output)
}
🔬 This is a nightly-only experimental API. (try_reserve)

new API

Tries to reserve the minimum capacity for exactly additional more elements to be inserted in the given String. After calling reserve_exact, capacity will be greater than or equal to self.len() + additional. 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.

Errors

If the capacity overflows, or the allocator reports a failure, then an error is returned.

Examples

#![feature(try_reserve)]
use std::collections::TryReserveError;

fn process_data(data: &str) -> Result<String, TryReserveError> {
    let mut output = String::new();

    // Pre-reserve the memory, exiting if we can't
    output.try_reserve(data.len())?;

    // Now we know this can't OOM in the middle of our complex work
    output.push_str(data);

    Ok(output)
}

Shrinks the capacity of this String to match its length.

Examples

Basic usage:

let mut s = String::from("foo");

s.reserve(100);
assert!(s.capacity() >= 100);

s.shrink_to_fit();
assert_eq!(3, s.capacity());

Shrinks the capacity of this String with a lower bound.

The capacity will remain at least as large as both the length and the supplied value.

If the current capacity is less than the lower limit, this is a no-op.

Examples

let mut s = String::from("foo");

s.reserve(100);
assert!(s.capacity() >= 100);

s.shrink_to(10);
assert!(s.capacity() >= 10);
s.shrink_to(0);
assert!(s.capacity() >= 3);

Appends the given char to the end of this String.

Examples

Basic usage:

let mut s = String::from("abc");

s.push('1');
s.push('2');
s.push('3');

assert_eq!("abc123", s);

Returns a byte slice of this String’s contents.

The inverse of this method is from_utf8.

Examples

Basic usage:

let s = String::from("hello");

assert_eq!(&[104, 101, 108, 108, 111], s.as_bytes());

Shortens this String to the specified length.

If new_len is greater than the string’s current length, this has no effect.

Note that this method has no effect on the allocated capacity of the string

Panics

Panics if new_len does not lie on a char boundary.

Examples

Basic usage:

let mut s = String::from("hello");

s.truncate(2);

assert_eq!("he", s);

Removes the last character from the string buffer and returns it.

Returns None if this String is empty.

Examples

Basic usage:

let mut s = String::from("foo");

assert_eq!(s.pop(), Some('o'));
assert_eq!(s.pop(), Some('o'));
assert_eq!(s.pop(), Some('f'));

assert_eq!(s.pop(), None);

Removes a char from this String at a byte position and returns it.

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

Panics

Panics if idx is larger than or equal to the String’s length, or if it does not lie on a char boundary.

Examples

Basic usage:

let mut s = String::from("foo");

assert_eq!(s.remove(0), 'f');
assert_eq!(s.remove(1), 'o');
assert_eq!(s.remove(0), 'o');
🔬 This is a nightly-only experimental API. (string_remove_matches)

new API

Remove all matches of pattern pat in the String.

Examples

#![feature(string_remove_matches)]
let mut s = String::from("Trees are not green, the sky is not blue.");
s.remove_matches("not ");
assert_eq!("Trees are green, the sky is blue.", s);

Matches will be detected and removed iteratively, so in cases where patterns overlap, only the first pattern will be removed:

#![feature(string_remove_matches)]
let mut s = String::from("banana");
s.remove_matches("ana");
assert_eq!("bna", s);

Retains only the characters specified by the predicate.

In other words, remove all characters c such that f(c) returns false. This method operates in place, visiting each character exactly once in the original order, and preserves the order of the retained characters.

Examples

let mut s = String::from("f_o_ob_ar");

s.retain(|c| c != '_');

assert_eq!(s, "foobar");

Because the elements are visited exactly once in the original order, external state may be used to decide which elements to keep.

let mut s = String::from("abcde");
let keep = [false, true, true, false, true];
let mut iter = keep.iter();
s.retain(|_| *iter.next().unwrap());
assert_eq!(s, "bce");

Inserts a character into this String at a byte position.

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

Panics

Panics if idx is larger than the String’s length, or if it does not lie on a char boundary.

Examples

Basic usage:

let mut s = String::with_capacity(3);

s.insert(0, 'f');
s.insert(1, 'o');
s.insert(2, 'o');

assert_eq!("foo", s);

Inserts a string slice into this String at a byte position.

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

Panics

Panics if idx is larger than the String’s length, or if it does not lie on a char boundary.

Examples

Basic usage:

let mut s = String::from("bar");

s.insert_str(0, "foo");

assert_eq!("foobar", s);

Returns a mutable reference to the contents of this String.

Safety

This function is unsafe because it does not check that the bytes passed to it are valid UTF-8. If this constraint is violated, it may cause memory unsafety issues with future users of the String, as the rest of the standard library assumes that Strings are valid UTF-8.

Examples

Basic usage:

let mut s = String::from("hello");

unsafe {
    let vec = s.as_mut_vec();
    assert_eq!(&[104, 101, 108, 108, 111][..], &vec[..]);

    vec.reverse();
}
assert_eq!(s, "olleh");

Returns the length of this String, in bytes, not chars or graphemes. In other words, it might not be what a human considers the length of the string.

Examples

Basic usage:

let a = String::from("foo");
assert_eq!(a.len(), 3);

let fancy_f = String::from("ƒoo");
assert_eq!(fancy_f.len(), 4);
assert_eq!(fancy_f.chars().count(), 3);

Returns true if this String has a length of zero, and false otherwise.

Examples

Basic usage:

let mut v = String::new();
assert!(v.is_empty());

v.push('a');
assert!(!v.is_empty());

Splits the string into two at the given byte index.

Returns a newly allocated String. self contains bytes [0, at), and the returned String contains bytes [at, len). at must be on the boundary of a UTF-8 code point.

Note that the capacity of self does not change.

Panics

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

Examples

let mut hello = String::from("Hello, World!");
let world = hello.split_off(7);
assert_eq!(hello, "Hello, ");
assert_eq!(world, "World!");

Truncates this String, removing all contents.

While this means the String will have a length of zero, it does not touch its capacity.

Examples

Basic usage:

let mut s = String::from("foo");

s.clear();

assert!(s.is_empty());
assert_eq!(0, s.len());
assert_eq!(3, s.capacity());

Creates a draining iterator that removes the specified range in the String and yields the removed chars.

Note: The element range is removed even if the iterator is not consumed until the end.

Panics

Panics if the starting point or end point do not lie on a char boundary, or if they’re out of bounds.

Examples

Basic usage:

let mut s = String::from("α is alpha, β is beta");
let beta_offset = s.find('β').unwrap_or(s.len());

// Remove the range up until the β from the string
let t: String = s.drain(..beta_offset).collect();
assert_eq!(t, "α is alpha, ");
assert_eq!(s, "β is beta");

// A full range clears the string
s.drain(..);
assert_eq!(s, "");

Removes the specified range in the string, and replaces it with the given string. The given string doesn’t need to be the same length as the range.

Panics

Panics if the starting point or end point do not lie on a char boundary, or if they’re out of bounds.

Examples

Basic usage:

let mut s = String::from("α is alpha, β is beta");
let beta_offset = s.find('β').unwrap_or(s.len());

// Replace the range up until the β from the string
s.replace_range(..beta_offset, "Α is capital alpha; ");
assert_eq!(s, "Α is capital alpha; β is beta");

Trait Implementations

Performs the conversion.

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

The resulting type after dereferencing.

Dereferences the value.

Mutably dereferences the value.

Performs the conversion.

Performs the conversion.

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

This method tests for !=.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

The resulting type after obtaining ownership.

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

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.