Macro bump_scope::bump_vec

macro_rules! bump_vec {
    [in $bump:expr] => { ... };
    [in $bump:expr; $($values:expr),* $(,)?] => { ... };
    [in $bump:expr; $value:expr; $count:expr] => { ... };
    [try in $bump:expr] => { ... };
    [try in $bump:expr; $($values:expr),* $(,)?] => { ... };
    [try in $bump:expr; $value:expr; $count:expr] => { ... };
}

Creates a BumpVec containing the arguments.

bump_vec! allows BumpVecs to be defined with the same syntax as array expressions. try makes the allocations fallible.

$bump can be a mutable Bump or BumpScope (anything where $bump.as_mut_scope() returns a &mut BumpScope).

Panics

If used without try, panics on allocation failure.

Errors

If used with try, errors on allocation failure.

Examples

There are three forms of this macro:

• Create an empty BumpVec:

let vec: BumpVec<i32> = bump_vec![in bump];
assert!(vec.is_empty());

• Create a BumpVec containing a given list of elements:

let vec = bump_vec![in bump; 1, 2, 3];
assert_eq!(vec[0], 1);
assert_eq!(vec[1], 2);
assert_eq!(vec[2], 3);

• Create a BumpVec from a given element and size:

let vec = bump_vec![in bump; 1; 3];
assert_eq!(vec, [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, bump_vec![in bump; 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 bump_vec![in bump; 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.