This is now possible with C++20, with syntax like: const std::string s = std::move(ss).str(); This is possible because the std::ostringstream class now has a str() overload that is rvalue-ref qualified: basic_string<charT, traits, Allocator> str() &&; // since C++20 This was added in P0408, revision 7, which was adopted into C++20. This is the exact approach … Read more
I’ve used a sequence of clear and str in the past: // clear, because eof or other bits may be still set. s.clear(); s.str(“”); Which has done the thing for both input and output stringstreams. Alternatively, you can manually clear, then seek the appropriate sequence to the begin: s.clear(); s.seekp(0); // for outputs: seek put … Read more
Personally, I find it very rare that I want to perform streaming into and out of the same string stream. Usually I want to either initialize a stream from a string and then parse it; or stream things to a string stream and then extract the result and store it. If you’re streaming to and … Read more