什么是`auto`用于之前？ [英] What was `auto` used for before?

问题描述

我知道在C ++ 11之前， auto 关键字具有完全不同的含义;它是一个存储类型说明符，指示具有自动存储类型（即放置在堆栈上）的对象。

I know that before C++11 the auto keyword had a completely different meaning; it was a storage type specifier indicating an object that has automatic storage type (ie, placed on the stack).

这是理论如何...你实际上使用这个关键字（语法），为什么？此外，我没有看到这个关键字在实际代码pre-C ++ 11;

That's how the theory goes... How would you actually use this keyword (syntax), and why? Also, I haven't seen this keyword in actual code pre-C++11; when was it useful (what time period)?

推荐答案

它用于声明一个具有自动存储持续时间的局部变量（即， on the stack）。

It was used to declare a local variable with automatic storage duration (i.e., "on the stack").

至少自从C90以来它是一个无用的关键字，因为自动存储持续时间是局部变量的默认存储持续时间。

At least since C90 it has been a useless keyword, since automatic storage duration is the default storage duration for a local variable.

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