Category 

C++-Specific Keywords 

Syntax  

bool <identifier>;

Description 

Use bool and the literals false and true to perform Boolean logic tests. 

The bool keyword represents a type that can take only the value false or true. The keywords false and true are Boolean literals with predefined values. false is numericallly zero and true is numerically one. These Boolean literals are rvalues; you cannot make an assignment to them. 

You can convert an rvalue that is of type bool to an rvalue that is int type. The numerical conversion sets false to zero and true becomes one. 

You can convert arithmetic, enumeration, pointer, or pointer to member rvalue types to an rvalue of type bool. A zero value, null pointer value, or null member pointer value is converted to false. Any other value is converted to true.