C ++中的$符号 [英] $ symbol in c++

问题描述

我从一个开源库中读取了以下代码.使我感到困惑的是美元符号的用法.任何人都可以在代码中阐明$的含义.非常感谢您的帮助！

I read the following code from an open source library. What confuses me is the usage of dollar sign. Can anyone please clarify the meaning of $ in the code. Your help is greatly appreciated!

   __forceinline MutexActive( void ) : $lock(LOCK_IS_FREE) {}
    void lock  ( void );
    __forceinline void unlock( void ) { 
      __memory_barrier();     // compiler must not schedule loads and stores around this point
      $lock = LOCK_IS_FREE; 
    }
  protected:
    enum ${ LOCK_IS_FREE = 0, LOCK_IS_TAKEN = 1 };
    Atomic $lock;

推荐答案

它已被用作 identifer 的一部分.

[C++11: 2.11/1]将标识符定义为任意长的字母和数字序列".它在紧随其后的语法中定义了字母和数字"，该名称仅命名数字，小写和大写罗马字母以及下划线字符，但也允许其他实现定义的字符"，其中大概是一个.

[C++11: 2.11/1] defines an identifier as "an arbitrarily long sequence of letters and digits." It defines "letters and digits" in a grammar given immediately above, which names only numeric digits, lower- and upper-case roman letters, and the underscore character explicitly, but does also allow "other implementation-defined characters", of which this is presumably one.

在这种情况下，$除了作为标识符的一部分外没有其他特殊含义.在这种情况下，为变量的名称.在变量名称的开始中并没有特殊的意义.

In this scenario the $ has no special meaning other than as part of an identifier — in this case, the name of a variable. There is no special significance with it being at the start of the variable name.

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