import { CurrencyAmount, Currency } from "@uniswap/sdk-core";
export declare enum ApprovalState {
    UNKNOWN = "UNKNOWN",
    NOT_APPROVED = "NOT_APPROVED",
    PENDING = "PENDING",
    APPROVED = "APPROVED"
}
export declare function useApproveCallback(amountToApprove?: CurrencyAmount<Currency>, spender?: string): [ApprovalState, () => Promise<void>];
export declare function useApproveCallbackFromInputCurrencyAmount(currencyAmountIn: CurrencyAmount<Currency> | undefined): [ApprovalState, () => Promise<void>];