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declare const emptyObjectSymbol: unique symbol;
/**
Represents a strictly empty plain object, the `{}` value.
When you annotate something as the type `{}`, it can be anything except `null` and `undefined`. This means that you cannot use `{}` to represent an empty plain object ([read more](https://stackoverflow.com/questions/47339869/typescript-empty-object-and-any-difference/52193484#52193484)).
@example
```
import type {EmptyObject} from 'type-fest';
// The following illustrates the problem with `{}`.
const foo1: {} = {}; // Pass
const foo2: {} = []; // Pass
const foo3: {} = 42; // Pass
const foo4: {} = {a: 1}; // Pass
// With `EmptyObject` only the first case is valid.
const bar1: EmptyObject = {}; // Pass
const bar2: EmptyObject = 42; // Fail
const bar3: EmptyObject = []; // Fail
const bar4: EmptyObject = {a: 1}; // Fail
```
Unfortunately, `Record<string, never>`, `Record<keyof any, never>` and `Record<never, never>` do not work. See {@link https://github.com/sindresorhus/type-fest/issues/395 #395}.
@category Object
*/
export type EmptyObject = {[emptyObjectSymbol]?: never};
/**
Returns a `boolean` for whether the type is strictly equal to an empty plain object, the `{}` value.
@example
```
import type {IsEmptyObject} from 'type-fest';
type Pass = IsEmptyObject<{}>; //=> true
type Fail = IsEmptyObject<[]>; //=> false
type Fail = IsEmptyObject<null>; //=> false
```
@see EmptyObject
@category Object
*/
export type IsEmptyObject<T> = T extends EmptyObject ? true : false;
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28 entries across 28 versions & 2 rubygems