Create a new list.

Creates a view of the contained identifiers as &strs.

Returns the number of elements the vector can hold without reallocating.

Examples

let vec: Vec<i32> = Vec::with_capacity(10);
assert_eq!(vec.capacity(), 10);

Converts the vector into Box<[T]>.

Note that this will drop any excess capacity. Calling this and converting back to a vector with into_vec is equivalent to calling shrink_to_fit.

Examples

let v = vec![1, 2, 3];

let slice = v.into_boxed_slice();

Any excess capacity is removed:

let mut vec = Vec::with_capacity(10);
vec.extend([1, 2, 3].iter().cloned());

assert_eq!(vec.capacity(), 10);
let slice = vec.into_boxed_slice();
assert_eq!(slice.into_vec().capacity(), 3);

Extracts a slice containing the entire vector.

Equivalent to &s[..].

Examples

use std::io::{self, Write};
let buffer = vec![1, 2, 3, 5, 8];
io::sink().write(buffer.as_slice()).unwrap();

Returns the number of elements in the vector, also referred to as its 'length'.

Examples

let a = vec![1, 2, 3];
assert_eq!(a.len(), 3);

Returns true if the vector contains no elements.

Examples

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

v.push(1);
assert!(!v.is_empty());

Create an instance from a list of nested meta items.

Create an instance from a syn::Meta by dispatching to the format-appropriate trait function. This generally should not be overridden by implementers. Read more

Create an instance from the presence of the word in the attribute with no additional options specified. Read more

Create an instance from a literal value of either foo = "bar" or foo("bar"). This dispatches to the appropriate method based on the type of literal encountered, and generally should not be overridden by implementers. Read more

Create an instance from a char literal in a value position.

Create an instance from a string literal in a value position.

Create an instance from a bool literal in a value position.

Performs the conversion.

Returns the "default value" for a type. Read more