https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111145
Bug ID: 111145 Summary: istream::operator>>(streambuf*) does not set gcount Product: gcc Version: 13.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: admin at computerquip dot com Target Milestone: --- Example code: https://godbolt.org/z/cW9Pe1c85 ``` #include <sstream> #include <iostream> int main() { std::ostringstream oss; std::istringstream iss("test"); iss >> oss.rdbuf(); std::cout << "gcount is " << iss.gcount() << "\n"; } ``` Here I'm expecting `iss.gcount()` to return 4 as `iss >> oss.rdbuf();`, as far as I can tell, fits under the conditions that should set the value accessed by gcount(). As per the godbolt link, it instead returns 0.