Macro alloc::vec 1.0.0
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[src]
macro_rules! vec { ($elem:expr; $n:expr) => { ... }; ($($x:expr),*) => { ... }; ($($x:expr,)*) => { ... }; }
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:
let v = vec![1, 2, 3]; assert_eq!(v[0], 1); assert_eq!(v[1], 2); assert_eq!(v[2], 3);
- Create a
Vec
from a given element and size:
let v = vec![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 nonstandard Clone
implementation. For
example, vec![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.