C++ Notes C16 Classes
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在閱讀 The C++ Programming Language 4th Edition - Bjarne Stroustrup 過程中的紀錄。
16.1 - Introduction
16.2 - Class Basics
16.2.1 - Member Functions
16.2.2 - Default Copying
16.2.3 - Access Control
16.2.4 - class and struct
16.2.5 - Constructors
16.2.6 - explicit Constructors
沒有特別理由的話，單一參數的 建構子 要宣告成 explicit，才是良好的習慣。
16.2.7 - In-Class Initializers
16.2.8 - In-Class Function Definitions
16.2.9 - Mutability
16.2.9.1 - Constant Member Functions
// const member function 不可以改變 class 內的 member 值 (y)
int Date::year() const { return y; }
16.2.9.2 - Physical and Logical Constness
有時候，const member function 仍然會需要改變 class 內部的狀態。如 string representation 是 const function, 但有個 cache 就可以避免每次都要重新建構 string, 此時就需要在 object Date 有異動時候，去修改 cache 的 string.
16.2.9.3 - mutable
定義 class member 為 mutable 就可以在 const function 中仍然可以修改這個 mutable member.
16.2.9.4 - Mutability through Indirection
16.2.10 - Self-Reference
// 能够 chained call functions, 如
d.add_day(1).add_month(1);
// 讓 function 回傳 object ref
Date& Date::add_day(int n) {
...
return *this;
}
16.2.11 - Member Access
16.2.12 - static Members
16.2.13 - Member Types
16.3 - Concrete Classes
16.3.1 - Member Functions
16.3.2 - Helping Functions
16.3.3 - Overloaded Operators
16.3.4 - The Significance of Concrete Classes
** 16.3 試做一次 **