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Specify behavior for getmetatable

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6
docs/metatable-type-functions.md
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@ -41,6 +41,9 @@ type Identity = setmetatable<{
}>
```
When a non-table type (number, boolean) is passed into the type function, it should result in an error. This includes classes.
If the type is an intersection/union of tables, then the metatable should be applied to every
### `getmetatable` Type Function
In the following code example, `ReversedIdentity` should evaluate to `{ __index: typeof(animal) }`:
@ -66,6 +69,9 @@ type metatable = {
type MetatableType = getmetatable<setmetatable<{}, metatable>>
```
If the type passed into the type function doesn't have a metatable and it *could* have a metatable (so primitives, singletons, classes, and tables), then it will return nil.
If the type passed in is an intersection/union, then it will return an interesction/union respectively.
## Drawbacks
Introducing a large library of "global" type functions can clutter naming space for users.