是否仍然使用register关键字？ [英] Is the register keyword still used?

问题描述

刚刚遇到C ++中的注册关键字，我想知道这似乎是一个好主意（保持某些变量在寄存器中）肯定编译器这样做默认情况下？

Just came across the register keyword in C++ and I wondered as this seems a good idea (keeping certain variables in a register) surely the compiler does this by default?

推荐答案

大多数实现只是忽略寄存器关键字（除非它强加了语法或语义错误）。

Most implementations just ignore the register keyword (unless it imposes a syntactical or semantical error).

标准也没有说任何东西必须保存在寄存器中;只是它的一个提示，该变量将被频繁使用的实现。其使用甚至​​已过时。

The standard also doesn't say that anything must be kept in a register; merely that it's a hint to the implementation that the variable is going to be used very often. Its use is even deprecated.

7.1.1存储类说明符[dcl.stc]

3）寄存器说明符是对实现的一个提示，这样声明的变量将被大量使用。 [注意：提示可以忽略，在大多数实现中，如果变量的地址被采用，它将被忽略。此使用已弃用（请参阅D.2）。 - end note]

7.1.1 Storage class specifiers [dcl.stc]

3) A register specifier is a hint to the implementation that the variable so declared will be heavily used. [ Note: The hint can be ignored and in most implementations it will be ignored if the address of the variable is taken. This use is deprecated (see D.2). — end note ]

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