C++ Primer Plus, Fourth Edition

Automatic Conversions and Type Casts for Classes

The next topic on the class menu is type conversion. We'll look into how C++ handles conversions to and from user-defined types. To set the stage, let's first review how C++ handles conversions for its built-in types. When you make a statement assigning a value of one standard type to a variable of another standard type, C++ automatically will convert the value to the same type as the receiving variable, providing the two types are compatible. For example, the following statements all generate numeric type conversions:

long count = 8;      // int value 8 converted to type long
double time = 11;    // int value 11 converted to type double
int side = 3.33;     // double value 3.33 converted to type int 3