macro_rules! smallvec { (@one $x:expr) => { ... }; ($elem:expr; $n:expr) => { ... }; ($($x:expr),*$(,)*) => { ... }; }
Expand description
Creates a SmallVec containing the arguments.
smallvec! allows SmallVecs to be defined with the same syntax as array expressions.
There are two forms of this macro:
- Create a
SmallVeccontaining a given list of elements:
let v: SmallVec<[_; 128]> = smallvec![1, 2, 3];
assert_eq!(v[0], 1);
assert_eq!(v[1], 2);
assert_eq!(v[2], 3);- Create a
SmallVecfrom a given element and size:
let v: SmallVec<[_; 0x8000]> = smallvec![1; 3];
assert_eq!(v, SmallVec::from_buf([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, smallvec![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.