C ++通过const指针或对const指针的引用传递 [英] c++ passing by const pointer or reference to const pointer

问题描述

我正在学习c ++，最近我读了一本书，建议您在可能的情况下（如果基本对象不会被更改）使用对const的引用。

I am learning c++, recently i read a book which gives a suggestion that you should use reference to const when possible (if base object will not be changed).

我有一个问题，如果可能的话，应该将引用传递给const指针而不是const指针，因为引用可以防止复制。如果不是，我什么时候应该使用对const指针的引用。

I have a question that should you pass reference to const pointer instead of const pointer, when possible, as reference prevents copied. If not when should i use reference to const pointer.

例如：

Node(..., Node *const next = nullptr);

OR

Node(..., Node* const& next = nullptr);

推荐答案

通过值引用传递const引用是一种好习惯（这会导致参数的复制）是一项繁重的操作。

Passing by const reference is good practice when passing by value (that causes copying of parameters) is a heavy operation.

例如，当您将具有某些属性的类传递给函数时，最好通过const引用传递它，另一方面，如果您要传递 int 之类的类型或仅使用指针，则最好不要使用引用，因为这样会由于取消引用过程而失去性能。

For example when you are passing a class with some properties to a function it's better to pass it by const reference, In other hand if your are passing types like int or just a pointer it's better not to use references because then you loos performance due to de-reference process.

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