HashMap::with_capacity

pub static fn with_capacity(int cap) -> HashMap<K, V>

use collections::map::{HashMap};

Creates an empty map with room for about cap buckets before it grows.

The bucket count is rounded up to a power of two, at least 8.

Parameters#

Returns#

HashMap<K, V>

Examples#

use collections::map::{HashMap};
use tests::assert;
let m: HashMap<int, string> = HashMap::with_capacity(100);
assert!(m.is_empty());
assert!(m.capacity() >= 100);

See also#

• HashMap: A hash map from keys of type K to values of type V.
• HashMap::new: Creates an empty map.
• HashMap::size: Returns the number of entries.
• HashMap::is_empty: Returns true when the map has no entries.
• HashMap::capacity: Returns the number of buckets.
• HashMap::clear: Removes every entry, keeping the bucket count.
• HashMap::keys: Returns the keys, in insertion order.
• HashMap::values: Returns the values, in the insertion order of their keys.