/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
declare class Stack<T> {
    constructor();
    push(element: T): void;
    pop(): T;
    size(): number;
}
declare interface GeometricShape {
    /**
     * Calculates the area of the shape.
     * @returns {number} The area of the shape.
     */
    calculateArea(): number;
}
/**
 * A function to capitalize the first letter of a string.
 * @param {string} str - The input string.
 * @returns {string} The capitalized string.
 */
declare function capitalizeFirstLetter(str: string): string;