Question

I have a class that extends ostringstream class.

Class A: public ostringstream
{

}

I want to read data of specified size and a specific offset from that object. So trying:

A a_;
a_ << data1 << data2;
string datax(a_[offset], size);

But getting a compile error at string datax statement.

error: no match for operator[] in ... 

How can I copy data from object a_ for a specified offset and size? I dont want to remove data from the object a_.

NOTE: The class was designed by someone else and cannot be modified.

Answer 1

I believe with the code you have you could do:

a_ << data1 << data2;
string datax(&a_.str()[offset], size);

which looks a bit ugly to me. Why not just use plain std::stringstream instead? (unless you have a strong reason to inherit from std::ostringstream.