深入理解C++对象模型:构造、封装与性能优化

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《深入理解C++对象模型》(Inside The C++ Object Model)是一本专注于剖析C++中支持面向对象编程底层机制的专业书籍。作者通过讲解构造函数语义、临时对象生成、封装支持、继承以及“虚函数”(virtual functions)和“虚继承”等核心概念,帮助程序员更深入地理解C++语言的工作原理,从而提高编码效率并增强信心。 书中,作者Michael Lippman澄清了关于C++中常被误解的开销和复杂性的观点,揭示了这些特性背后隐藏的成本和权衡。他详述了各种实现模型的起源,指出它们可能的发展方向,并解释了为何它们呈现出当前的形式。通过探讨C++对象模型的语义含义,这本书阐述了这个模型如何影响实际编程实践。 本书的亮点包括: 1. 深入解析C++对象模型在支持面向对象编程时所隐含的程序行为。读者能够学习到如何利用这些特性设计出结构清晰、高效且可维护的代码。 2. 对面向对象特性的基础实现进行剖析,揭示其中的内在工作原理和潜在的性能影响。这有助于开发者在选择和设计时做出明智决策,权衡功能与性能之间的关系。 3. 分析了这些特性对程序转换(如编译优化)的影响,这对于性能优化和系统调优至关重要。书中提供了丰富的代码示例、图表以及性能测量数据,使抽象的概念更加具体化。 4. 通过CodeSaw在线学习工具,读者可以直接在浏览器中实验书中的代码,这是一种价值附加服务,极大地提升了学习体验和实践能力。 如果你是一名希望深入理解C++内部机制的程序员,《深入理解C++对象模型》将是你不可或缺的参考资料。它不仅提供了理论知识,还提供了实践操作的平台,让你的编程技能得到全面提升。

帮我写出以下java代码:Add a class Bubble that extends Shape. The Bubble class has an instance variable called radius of type double that represents the radius of the bubble. The constructor of the Bubble class takes an x and a y as arguments, which represent the position of the new bubble. The radius of a new bubble is always 10 and never changes after that. The isVisible method indicates whether the bubble is currently visible inside a window of width w and height h (position (0, 0) is in the upper-left corner of the window). The bubble is considered visible if at least one pixel of the bubble is visible. Therefore a bubble might be visible even when its center is outside the window, as long as the edge of the bubble is still visible inside the window. The code of the isVisible method is a little bit complex, mostly because of the case where the center of the circle is just outside one of the corners of the window. So here is the code of the isVisible method, which you can directly copy-paste into your assignment: // Find the point (wx, wy) inside the window which is closest to the // center (x, y) of the circle. In other words, find the wx in the // interval [0, w - 1] which is closest to x, and find the wy in the // interval [0, h - 1] which is closest to y. // If the distance between (wx, wy) and (x, y) is less than the radius // of the circle (using Pythagoras's theorem) then at least part of // the circle is visible in the window. // Note: if the center of the circle is inside the window, then (wx, wy) // is the same as (x, y), and the distance is 0. public boolean isVisible(int w, int h) { double x = getX(); double y = getY(); double wx = (x < 0 ? 0 : (x > w - 1 ? w - 1 : x)); double wy = (y < 0 ? 0 : (y > h - 1 ? h - 1 : y)); double dx = wx - x; double dy = wy - y; return dx * dx + dy * dy <= radius * radius; } The isIn method indicates whether the point at coordinates (x, y) (which are the arguments of the method) is currently inside the bubble or not. The edge of the bubble counts as being inside of the bubble. HINT: use Pythagoras's theorem to compute the distance from the center of the bubble to the point (x, y). The draw method uses the graphics object g to draw the bubble. HINT: remember that the color of the graphics object g is changed in the draw method of the superclass of Bubble. Also add a testBubble method to test all your methods (including inherited methods, but excluding the isVisible method, which I provide, and excluding the draw method since it requires as argument a graphics object g that you

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