# WritableKeys

Selects writable keys from a structural type.

## Signatures

```ts
export type WritableKeys<T> = {
    [K in keyof T]-?: IfEquals<{
        [P in K]: T[P];
    }, {
        -readonly [P in K]: T[P];
    }, K>;
}[keyof T];
```

## Why

Host props must not promise assignment to browser-owned readonly DOM fields.

## Ownership and lifetime

Type-only and resource-free.