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IsSymbolLiteral<T>

IsSymbolLiteral<T> = LiteralCheck<T, symbol>

Defined in: packages/react-querybuilder/src/types/type-fest/is-literal.ts:243

Returns a boolean for whether the given type is a symbol literal type.

Useful for:

  • providing strongly-typed functions when given literal arguments
  • type utilities, such as when constructing parsers and ASTs

Type Parameters​

Type Parameter
T

Example​

import type {IsSymbolLiteral} from 'type-fest';

type Get<Obj extends Record<symbol, number>, Key extends keyof Obj> =
	IsSymbolLiteral<Key> extends true
		? Obj[Key]
		: number;

function get<Obj extends Record<symbol, number>, Key extends keyof Obj>(o: Obj, key: Key) {
	return o[key] as Get<Obj, Key>;
}

const symbolLiteral = Symbol('literal');
const symbolValue: symbol = Symbol('value');

get({[symbolLiteral]: 1} as const, symbolLiteral);
//=> 1

get({[symbolValue]: 1} as const, symbolValue);
//=> number
caution

API documentation is generated from the latest commit on the main branch. It may be somewhat inconsistent with official releases of React Query Builder.