export declare function isStr(str?: unknown): str is string;
export declare namespace isStr {
    var toString: () => string;
}
export declare function isText(str?: unknown): str is string;
export declare namespace isText {
    var toString: () => string;
}
export declare function isNumber(str?: unknown): str is number;
export declare namespace isNumber {
    var toString: () => string;
}
export declare function isProto(str?: string): boolean;
export declare namespace isProto {
    var toString: () => string;
}