"rwawryk" <ra****@gazeta.pl> wrote...
Does anybody know how to implement parametrized stream operator (such as
setw, setfill)? I need to put into the stream variable of type char*
without terminating NULL. It would be great if I had the manipulator which allows
to determine maximum number of characters ( let's assume maxw( char* str, int
maxlen ) ).
example:
cout << maxw("Crocodile", 5 );
Croco
thanx in advance
ralfer
ps. prefer templates to macros... :)
(a) If you need to put several chars into the stream, just put
them into the stream. No "terminating NULL" is copied into the
stream. cout << string("Crocodile").substr(5); should do it.
(b) Usually parameterised manipulators are written either as
functions that return special objects or just as classes [that
you construct right there], which, when output to a stream, do
something to the stream:
struct maxw {
maxw(const char*, int); // constructor
ostream& print(ostream&) const; // output
// some data
};
ostream& operator <<(ostream& os, const maxw& m) {
return m.print(os);
}
maxw::maxw(const char* s, int n) : ....
ostream& maxw::print(ostream& os) const {
// do something to the stream to output what you need
// in a special way
}
HTH
Victor
