C++核心準(zhǔn)則C.131: 避免無意義的getters和setters?

C.131: Avoid trivial getters and setters

C.131: 避免無意義的getters和setters?

Reason(原因)

A trivial getter or setter adds no semantic value; the data item could just as well be public.

無意義的getter和setter不會增加任何語義上的價值，數(shù)據(jù)項只要定義為public就好。

Example(示例)

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
};

Consider making such a class a struct -- that is, a behaviorless bunch of variables, all public data and no member functions.

考慮將這樣的類定義為struct--也就是說，不包含行為的數(shù)據(jù)群，所有數(shù)據(jù)都公開，沒有成員函數(shù)。

struct?Point?{
????int?x?{0};
????int?y?{0};
};

Note that we can put default initializers on member variables:?C.49: Prefer initialization to assignment in constructors.

注意我們可以為成員變量設(shè)置初始化器：C.49:初始化比在構(gòu)造函數(shù)中復(fù)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.

這條準(zhǔn)則的關(guān)鍵是getter/setter的語義是不是有意義。如果不能完全定義“無意義”，考慮如果getter/setter是公有成員的話是否存在任何的不同。有意義的語義的示例：維持類的不變量或者在內(nèi)部數(shù)據(jù)類型和接口數(shù)據(jù)類型之間進(jìn)行的轉(zhuǎn)換。

Enforcement(實施建議)

Flag multiple get and set member functions that simply access a member without additional semantics.

如果存在多個get和set成員函數(shù)，只是簡單地訪問數(shù)據(jù)成員卻不包含附加意義，進(jìn)行提示。

原文鏈接：

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

覺得本文有幫助？請分享給更多人。

關(guān)注【面向?qū)ο笏伎肌枯p松學(xué)習(xí)每一天！

面向?qū)ο箝_發(fā)，面向?qū)ο笏伎迹?/p>