Function ofSetMutable

ofSetMutable<V>(
options?: MapSetOpts<V>,
): IMapOfMutableExtended<V, ReadonlyMap<string, V>>
Returns a IMapOfMutableExtended that uses a set to hold values. This means that only unique values are stored under each key. By default it uses the JSON representation to compare items.

Options: { hash: toStringFn } }

hash is a Util.ToString function: (object) => string. By default it uses JSON.stringify.
Type Parameters
- V
Parameters
- Optionaloptions: MapSetOpts<V>
Returns IMapOfMutableExtended<V, ReadonlyMap<string, V>>
Example: Only storing the newest three items per key
```
const map = mapOfSetMutable();
map.add(`hello`, [1, 2, 3, 1, 2, 3]);
const hello = map.get(`hello`); // [1, 2, 3]
```
Example
```
const hash = (v) => v.name; // Use name as the key
const map = mapOfSetMutable(hash);
map.add(`hello`, {age:40, name: `Mary`});
map.add(`hello`, {age:29, name: `Mary`}); // Value ignored as same name exists
```