1.5. Pointers to components of class 1.5.1. Pointers to components - data

You can define a pointer to data components.

datatype (class_name:: * pointer_name)

You can include its initializer in the definition of a pointer.

& class_name:: component_name

Example:

double (complex:: * pdat) = & complex:: re;

Naturally, in this case, the data members must have the status of open (pubic). After the pointer is initialized, it can be used to access the data of the object.

complexc (10.2,3.6); c / * pdat = 22.2; // the value of the re field of the object c has changed.

A pointer to a class component can be used as an actual parameter when calling a function. If pointers to the object and to the component are defined, then access to the component using the operation

'-> *'. pointer_to_object -> * pointer_to_component ''

Example 1.5.1

double (complex:: * pdat) = & complex:: re;

complex C (10.2,3.6);

complex * pcom = & C;

pcom -> * pdat = 22.2;

// You can determine the type of the pointer to the class data-components:

typedef double (complex :: * PDAT);

void f (complex c, PDAT pdat) {c. * pdat = 0;}

complex c;

PDAT pdat = & complex :: re; f (c, pdat);

pdat = & complex :: im; f (c, pdat);