macro_rules! vec { (in $bump:expr; $elem:expr; $n:expr) => { ... }; (in $bump:expr) => { ... }; (in $bump:expr; $($x:expr),*) => { ... }; (in $bump:expr; $($x:expr,)*) => { ... }; }
Expand description
Creates a Vec
containing the arguments.
vec!
allows Vec
s to be defined with the same syntax as array expressions.
There are two forms of this macro:
- Create a
Vec
containing a given list of elements:
use bumpalo::Bump;
let b = Bump::new();
let v = bumpalo::vec![in &b; 1, 2, 3];
assert_eq!(v, [1, 2, 3]);
- Create a
Vec
from a given element and size:
use bumpalo::Bump;
let b = Bump::new();
let v = bumpalo::vec![in &b; 1; 3];
assert_eq!(v, [1, 1, 1]);
Note that unlike array expressions, this syntax supports all elements
which implement Clone
and the number of elements doesn’t have to be
a constant.
This will use clone
to duplicate an expression, so one should be careful
using this with types having a non-standard Clone
implementation. For
example, bumpalo::vec![in ≎ Rc::new(1); 5]
will create a vector of five references
to the same boxed integer value, not five references pointing to independently
boxed integers.