C.131: Avoid trivial getters and setters
C.131: 避免无意义的getters和setters
Reason(原因)
A trivial getter or setter adds no semantic value; the data item could just as well be public.
无意义的getter和setter不会增加任何语义上的价值，数据项只要定义为public就好。
Example(示例)
<code>class Point { // Bad: verbose int x; int y;public: Point(int xx, int yy) : x{xx}, y{yy} { } int get_x() const { return x; } void set_x(int xx) { x = xx; } int get_y() const { return y; } void set_y(int yy) { y = yy; } // no behavioral member functions};/<code>Consider making such a class a struct -- that is, a behaviorless bunch of variables, all public data and no member functions.
考虑将这样的类定义为struct--也就是说，不包含行为的数据群，所有数据都公开，没有成员函数。
<code>struct Point { int x {0}; int y {0};};/<code>Note that we can put default initializers on member variables: C.49: Prefer initialization to assignment in constructors.
注意我们可以为成员变量设置初始化器：C.49:初始化比在构造函数中复制更好。
Note(注意)
The key to this rule is whether the semantics of the getter/setter are trivial. While it is not a complete definition of "trivial", consider whether there would be any difference beyond syntax if the getter/setter was a public data member instead. Examples of non-trivial semantics would be: maintaining a class invariant or converting between an internal type and an interface type.
这条准则的关键是getter/setter的语义是不是有意义。如果不能完全定义“无意义”，考虑如果getter/setter如果是公有成员的话是否存在任何的不同。有意义的语义的示例：维持类的不变量或者在内部数据类型和接口数据类型之间进行转换。
Enforcement(实施建议)
Flag multiple get and set member functions that simply access a member without additional semantics.
如果存在多个get和set成员函数只是简单地访问数据成员却不包含附加意义，进行提示。
原文链接：
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c130-for-making-deep-copies-of-polymorphic-classes-prefer-a-virtual-clone-function-instead-of-copy-constructionassignment
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