/** Combines members of an intersection into a readable type. */
export type Compute<type> = {
    [key in keyof type]: type[key];
} & unknown;
declare const symbol: unique symbol;
/**
 * Creates a branded type of `T` with the brand `U`.
 *
 * @example
 * ```ts
 * type Result = Branded<string, 'foo'>
 * //   ^? type Result = string & { [symbol]: 'foo' }
 * ```
 */
export type Branded<T, U> = T & {
    [symbol]: U;
};
/**
 * Filters out all members of `T` that are not `P`
 *
 * @example
 * ```ts
 * type Result = Filter<['a', 'b', 'c'], 'b'>
 * //   ^? type Result = ['a', 'c']
 * ```
 *
 * @internal
 */
export type Filter<T extends readonly unknown[], P, Acc extends readonly unknown[] = []> = T extends readonly [infer F, ...infer Rest extends readonly unknown[]] ? [F] extends [P] ? Filter<Rest, P, [...Acc, F]> : Filter<Rest, P, Acc> : readonly [...Acc];
/**
 * Checks if `T` can be narrowed further than `U`
 *
 * @example
 * ```ts
 * type Result = IsNarrowable<'foo', string>
 * //   ^? true
 * ```
 */
export type IsNarrowable<T, U> = IsNever<(T extends U ? true : false) & (U extends T ? false : true)> extends true ? false : true;
/**
 * Checks if `T` is `never`
 *
 * @example
 * ```ts
 * type Result = IsNever<never>
 * //   ^? type Result = true
 * ```
 */
export type IsNever<T> = [T] extends [never] ? true : false;
/**
 * Removes `readonly` from all properties of an object.
 *
 * @internal
 */
export type Mutable<type extends object> = {
    -readonly [key in keyof type]: type[key];
};
/**
 * Evaluates boolean "or" condition for `T` properties.
 *
 * * @example
 * ```ts
 * type Result = Or<[false, true, false]>
 * //   ^? type Result = true
 * ```
 *
 * @example
 * ```ts
 * type Result = Or<[false, false, false]>
 * //   ^? type Result = false
 * ```
 *
 * @internal
 */
export type Or<T extends readonly unknown[]> = T extends readonly [infer Head, ...infer Tail] ? Head extends true ? true : Or<Tail> : false;
/**
 * Checks if `T` is `undefined`
 *
 * @example
 * ```ts
 * type Result = IsUndefined<undefined>
 * //   ^? type Result = true
 * ```
 *
 * @internal
 */
export type IsUndefined<T> = [undefined] extends [T] ? true : false;
/**
 * Checks if type `T` is the `unknown` type.
 *
 * @internal
 */
export type IsUnknown<T> = unknown extends T ? ([T] extends [null] ? false : true) : false;
/** @internal */
export type MaybePromise<T> = T | Promise<T>;
/**
 * Makes attributes on the type T required if required is true.
 *
 * @example
 * ```ts
 * MaybeRequired<{ a: string, b?: number }, true>
 * // { a: string, b: number }
 *
 * MaybeRequired<{ a: string, b?: number }, false>
 * // { a: string, b?: number }
 * ```
 *
 * @internal
 */
export type MaybeRequired<T, required extends boolean> = required extends true ? ExactRequired<T> : T;
/**
 * Assigns the properties of U onto T.
 *
 * @example
 * ```ts
 * Assign<{ a: string, b: number }, { a: undefined, c: boolean }>
 * // { a: undefined, b: number, c: boolean }
 * ```
 *
 * @internal
 */
export type Assign<T, U> = Assign_inner<T, U> & U;
/** @internal */
export type Assign_inner<T, U> = {
    [K in keyof T as K extends keyof U ? (U[K] extends void ? never : K) : K]: K extends keyof U ? U[K] : T[K];
};
/**
 * Constructs a type by excluding `undefined` from `T`.
 *
 * @example
 * ```ts
 * NoUndefined<string | undefined>
 * // string
 * ```
 *
 * @internal
 */
export type NoUndefined<T> = T extends undefined ? never : T;
/**
 * Strict version of built-in Omit type
 *
 * @internal
 */
export type Omit<type, keys extends keyof type> = Pick<type, Exclude<keyof type, keys>>;
/**
 * Creates a type that is a partial of T, but with the required keys K.
 *
 * @example
 * ```ts
 * PartialBy<{ a: string, b: number }, 'a'>
 * // { a?: string, b: number }
 * ```
 *
 * @internal
 */
export type PartialBy<T, K extends keyof T> = Omit<T, K> & ExactPartial<Pick<T, K>>;
export type RecursiveArray<T> = T | readonly RecursiveArray<T>[];
/**
 * Creates a type that is T with the required keys K.
 *
 * @example
 * ```ts
 * RequiredBy<{ a?: string, b: number }, 'a'>
 * // { a: string, b: number }
 * ```
 *
 * @internal
 */
export type RequiredBy<T, K extends keyof T> = Omit<T, K> & ExactRequired<Pick<T, K>>;
/**
 * Returns truthy if `array` contains `value`.
 *
 * @example
 * ```ts
 * Some<[1, 2, 3], 2>
 * // true
 * ```
 *
 * @internal
 */
export type Some<array extends readonly unknown[], value> = array extends readonly [
    value,
    ...unknown[]
] ? true : array extends readonly [unknown, ...infer rest] ? Some<rest, value> : false;
/**
 * Prints custom error message
 *
 * @param messages - Error message
 * @returns Custom error message
 *
 * @example
 * ```ts
 * type Result = TypeErrorMessage<'Custom error message'>
 * //   ^? type Result = ['Error: Custom error message']
 * ```
 */
export type TypeErrorMessage<messages extends string | string[]> = messages extends string ? [
    `Error: ${messages}`
] : {
    [key in keyof messages]: messages[key] extends infer message extends string ? `Error: ${message}` : never;
};
/** @internal */
export type UnionToTuple<union, last = LastInUnion<union>> = [union] extends [never] ? [] : [...UnionToTuple<Exclude<union, last>>, last];
/** @internal */
export type LastInUnion<U> = UnionToIntersection<U extends unknown ? (x: U) => 0 : never> extends (x: infer l) => 0 ? l : never;
/** @internal */
export type UnionToIntersection<union> = (union extends unknown ? (arg: union) => 0 : never) extends (arg: infer i) => 0 ? i : never;
/** @internal */
export type IsUnion<union, union2 = union> = union extends union2 ? ([union2] extends [union] ? false : true) : never;
/** @internal */
export type MaybePartial<type, enabled extends boolean | undefined> = enabled extends true ? Compute<ExactPartial<type>> : type;
export type ExactPartial<type> = {
    [key in keyof type]?: type[key] | undefined;
};
/** @internal */
export type ExactRequired<type> = {
    [key in keyof type]-?: Exclude<type[key], undefined>;
};
export type OneOf<union extends object, fallback extends object | undefined = undefined, keys extends KeyofUnion<union> = KeyofUnion<union>> = union extends infer item ? Compute<item & {
    [key in Exclude<keys, keyof item>]?: fallback extends object ? key extends keyof fallback ? fallback[key] : undefined : undefined;
}> : never;
/** @internal */
export type KeyofUnion<type> = type extends type ? keyof type : never;
/** @internal */
export type Undefined<type> = {
    [key in keyof type]?: undefined;
};
/**
 * Loose version of {@link Omit}
 * @internal
 */
export type LooseOmit<type, keys extends string> = Pick<type, Exclude<keyof type, keys>>;
/** @internal */
export type UnionCompute<type> = type extends object ? Compute<type> : type;
/** @internal */
export type UnionLooseOmit<type, keys extends string> = type extends any ? LooseOmit<type, keys> : never;
/**
 * Construct a type with the properties of union type T except for those in type K.
 * @example
 * ```ts
 * type Result = UnionOmit<{ a: string, b: number } | { a: string, b: undefined, c: number }, 'a'>
 * // { b: number } | { b: undefined, c: number }
 * ```
 *
 * @internal
 */
export type UnionOmit<type, keys extends keyof type> = type extends any ? Omit<type, keys> : never;
/**
 * Construct a type with the properties of union type T except for those in type K.
 * @example
 * ```ts
 * type Result = UnionOmit<{ a: string, b: number } | { a: string, b: undefined, c: number }, 'a'>
 * // { b: number } | { b: undefined, c: number }
 * ```
 *
 * @internal
 */
export type UnionPick<type, keys extends keyof type> = type extends any ? Pick<type, keys> : never;
/**
 * Creates a type that is a partial of T, but with the required keys K.
 *
 * @example
 * ```ts
 * PartialBy<{ a: string, b: number } | { a: string, b: undefined, c: number }, 'a'>
 * // { a?: string, b: number } | { a?: string, b: undefined, c: number }
 * ```
 *
 * @internal
 */
export type UnionPartialBy<T, K extends keyof T> = T extends any ? PartialBy<T, K> : never;
/**
 * Creates a type that is T with the required keys K.
 *
 * @example
 * ```ts
 * RequiredBy<{ a?: string, b: number } | { a?: string, c?: number }, 'a'>
 * // { a: string, b: number } | { a: string, c?: number }
 * ```
 *
 * @internal
 */
export type UnionRequiredBy<T, K extends keyof T> = T extends any ? RequiredBy<T, K> : never;
export {};
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