declare const make: <A>(value: A) => Effect.Effect<Ref<A>>

declare const get: <A>(self: Ref<A>) => Effect.Effect<A>

export interface Ref<in out A> extends Ref.Variance<A>, Effect.Effect<A>, Readable.Readable<A> {
  modify<B>(f: (a: A) => readonly [B, A]): Effect.Effect<B>
  readonly [Unify.typeSymbol]?: unknown
  readonly [Unify.unifySymbol]?: RefUnify<this>
  readonly [Unify.ignoreSymbol]?: RefUnifyIgnore
}

export interface Variance<in out A> {
  readonly [RefTypeId]: {
    readonly _A: Types.Invariant<A>
  }
}

export interface RefUnify<A extends { [Unify.typeSymbol]?: any }> extends Effect.EffectUnify<A> {
  Ref?: () => Extract<A[Unify.typeSymbol], Ref<any>>
}

export interface RefUnifyIgnore extends Effect.EffectUnifyIgnore {
  Effect?: true
}

declare const RefTypeId: unique symbol

type RefTypeId = typeof RefTypeId

declare const unsafeMake: <A>(value: A) => Ref<A>

declare const getAndSet: {
  <A>(value: A): (self: Ref<A>) => Effect.Effect<A>
  <A>(self: Ref<A>, value: A): Effect.Effect<A>
}

declare const getAndUpdate: {
  <A>(f: (a: A) => A): (self: Ref<A>) => Effect.Effect<A>
  <A>(self: Ref<A>, f: (a: A) => A): Effect.Effect<A>
}

declare const getAndUpdateSome: {
  <A>(pf: (a: A) => Option.Option<A>): (self: Ref<A>) => Effect.Effect<A>
  <A>(self: Ref<A>, pf: (a: A) => Option.Option<A>): Effect.Effect<A>
}

declare const modify: {
  <A, B>(f: (a: A) => readonly [B, A]): (self: Ref<A>) => Effect.Effect<B>
  <A, B>(self: Ref<A>, f: (a: A) => readonly [B, A]): Effect.Effect<B>
}

declare const modifySome: {
  <B, A>(fallback: B, pf: (a: A) => Option.Option<readonly [B, A]>): (self: Ref<A>) => Effect.Effect<B>
  <A, B>(self: Ref<A>, fallback: B, pf: (a: A) => Option.Option<readonly [B, A]>): Effect.Effect<B>
}

declare const set: {
  <A>(value: A): (self: Ref<A>) => Effect.Effect<void>
  <A>(self: Ref<A>, value: A): Effect.Effect<void>
}

declare const setAndGet: {
  <A>(value: A): (self: Ref<A>) => Effect.Effect<A>
  <A>(self: Ref<A>, value: A): Effect.Effect<A>
}

declare const update: {
  <A>(f: (a: A) => A): (self: Ref<A>) => Effect.Effect<void>
  <A>(self: Ref<A>, f: (a: A) => A): Effect.Effect<void>
}

declare const updateAndGet: {
  <A>(f: (a: A) => A): (self: Ref<A>) => Effect.Effect<A>
  <A>(self: Ref<A>, f: (a: A) => A): Effect.Effect<A>
}

declare const updateSome: {
  <A>(f: (a: A) => Option.Option<A>): (self: Ref<A>) => Effect.Effect<void>
  <A>(self: Ref<A>, f: (a: A) => Option.Option<A>): Effect.Effect<void>
}

declare const updateSomeAndGet: {
  <A>(pf: (a: A) => Option.Option<A>): (self: Ref<A>) => Effect.Effect<A>
  <A>(self: Ref<A>, pf: (a: A) => Option.Option<A>): Effect.Effect<A>
}