macro_rules! vec {
() => { ... };
($elem:expr; $n:expr) => { ... };
($($x:expr),+ $(,)?) => { ... };
}Expand description
Creates a Vec containing the arguments.
vec! allows Vecs to be defined with the same syntax as array expressions.
There are two forms of this macro:
- Create a
Veccontaining a given list of elements:
- Create a
Vecfrom a given element and size:
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.
Also, note that vec![expr; 0] is allowed, and produces an empty vector.
This will still evaluate expr, however, and immediately drop the resulting value, so
be mindful of side effects.