Re: inheriting from ostream to customize standard output
On Mar 29, 11:48 am, aaragon <alejandro.ara...@gmail.com> wrote:
I was wondering if there is an easy way that one could create
a custom class that inherits from std::ostream to override the
functionality of operator<<.
No, thank goodness. The behavior of the operator<< is part of
the contract of ostream, and too much other code counts on it.
What you can do is define your own streaming class; when
appropriate, it could delegate to an ostream.
Since I work with several processes, I want to avoid some of them to
print information to standard output (or enable that to print
information concurrently).
I tried the following but it didn't work:
class Output_strem : public std::ostream {
typedef std::ostream base_type;
public:
Output_strem() : base_type() {}
template <typename T>
std::ostream& operator<<(T t) {
#ifdef MPI
std::ostream& os = *this;
os<<"["<<Parallel_base::rank_<<"] ";
#endif
return *this;
}
};
Can someone point me in the right direction?
Use delegation instead of inheritance.
--
James Kanze