Creating ostream manipulators for a specific class
- by petersohn
I have a class that is derived from ostream:
class my_ostream: public std::ostream
{
// ...
}
I want to make a manipulator (for example do_something), that works specifically to this class, like this:
my_ostream s;
s << "some text" << do_something << "some more text";
I did the following:
std::ostream &do_something(std::ostream &os)
{
my_ostream *s = dynamic_cast<my_ostream*>(&os);
if (s != NULL)
{
// do something
}
return os;
}
This works, but is rather ugly. I tried the following:
my_ostream &do_something(my_ostream &s)
{
// do something
return s;
}
This doesn't work. I also tried another approach:
class my_ostream: public std::ostream
{
// ...
my_ostream &operator<<(const do_something & x)
{
// do something
return *this;
}
}
This still doesn't work.
