istream_withassign::operator =

Syntax

istream& operator =( const istream& ris );

istream& operator =( streambuf* psb );

Remarks

The first overloaded assignment operator assigns the specified istream object to this istream_withassign object.

The second operator attaches a streambuf object to an existing istream_withassign object, and it initializes the state of the istream_withassign object. This operator is often used in conjunction with the void-argument constructor.

Example 1

char buffer[100];

class xistream; // A special-purpose class derived from istream

extern xistream xin; // An xistream object constructed elsewhere

cin = xin; // cin is reassigned to xin

cin >> buffer; // xin used instead of cin

Example 2

char buffer[100];

extern filedesc fd; // A file descriptor for an open file

filebuf fb( fd ); // Construct a filebuf attached to fd

cin = &fb; // fb associated with cin

cin >> buffer; // cin now gets its intput from the fb file

See Also

istream_withassign::istream_withassign, cin