它调用操作符的一个基类的衍生工具的集合。

It invokes operator on a collection of derivatives of the base class.

youdao

调用操作符是一对圆括号，括住传递给函数的实参列表（可能为空）。

The call operator is a pair of parentheses that encloses a (possibly empty) list of arguments that we pass to the function.

youdao

执行成员函数和执行其他函数相似：要调用函数，可将调用操作符（（））放在函数名之后。

We execute a member function in much the same way as we do any function: To call a function, we follow the function name by the call operator (the "()" operator).

youdao