C++中，auto关键字有哪些乱用的情况?平时使用有哪些坑？ 第1页

乱用的话代码的可读性会变差。auto还是需要放在编码规范中的。

其实很多团队的编码规范里面都包含了auto的使用规范。google编码规范里面也有，它的原则可以参考。其中的精髓大概就是这样一段话：

The fundamental rule is: use type deduction only to make the code clearer or safer, and do not use it merely to avoid the inconvenience of writing an explicit type. When judging whether the code is clearer, keep in mind that your readers are not necessarily on your team, or familiar with your project, so types that you and your reviewer experience as unnecessary clutter will very often provide useful information to others. For example, you can assume that the return type of make_unique<Foo>() is obvious, but the return type of MyWidgetFactory() probably isn't.

它这里说的type deduction包含了auto和模板参数，仅仅只是关注auto的用法也一样是适用的。

google编码规范里面对于各种情况都列举了，定义自己的规范时可以参考。

就我个人体会，适合使用auto的情况随手能列出以下几种：

       1、for(auto it = container.begin(); it != container.end(); ++it)    for(const auto& item: container)    for(auto&& item: container) 2、auto f = [](){}; 3、auto p = new very_very_long_class_name;    auto p = std::make_shared<class_name>(...);    auto p = std::make_unique<class_name>(...);    auto p = std::make_tuple(5, 2.0f, std::string("123")); 4、auto [it, ok] = my_map.insert(...);    for(auto&& [key, value]: my_map)