The ANSI/ISO C++ Standard has added a new type (new to C++, that is), called
bool. It’s named in honor of the English mathematician George Boole, who developed a mathematical representation of the laws of logic. In computing, a Boolean variable is one whose value can be either
false. In the past, C++, like C, has not had a Boolean type. Instead, as you’ll see in greater detail in Chapters 5 and 6, C++ interprets nonzero values as true and zero values as false. Now, however, you can use the
bool type to represent true and false, and the predefined literals
false represent those values. That is, you can make statements like the following:
bool is_ready = true;
false can be converted to type ...