C.Plus.Plus.Primer.4th.Edition [Electronic resources] نسخه متنی

2.6. Typedef Names

A typedef lets us define a synonym for a type:

typedef double wages;       //  wages is a synonym for double
typedef int exam_score;     //  exam_score is a synonym for int
typedef wages salary;       //  indirect synonym for double

A typedef name can be used as a type specifier:

wages hourly, weekly;     // double hourly, weekly;
exam_score test_result;   // int test_result;

A typedef definition begins with the keyword typedef, followed by the data type and identifier. The identifier, or typedef name, does not introduce a new type but rather a synonym for the existing data type. A typedef name can appear anywhere in a program that a type name can appear.

Typedefs are commonly used for one of three purposes:

To hide the implementation of a given type and emphasize instead the purpose for which the type is used

To streamline complex type definitions, making them easier to understand

To allow a single type to be used for more than one purpose while making the purpose clear each time the type is used