[Asio] streambuf exceptions
I'm using an asio::streambuf to read and write data to a socket. Despite my best efforts, I can't get the streambuf to throw an exception if I consume too much. I'm trying to get it to throw an exception so I can test an error case. The documentation says streambuf::consume will throw an std::length error if the requested amount to read is greater than the input stream size ( http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/reference/basic_str...). But in my test program, this did not happen. Do I need to enable exception throwing somehow? Or is streambuf working as intended and not supposed to throw an exception? Here is my test program: #include <iostream> #include <boost/asio.hpp> using namespace std; int main() { char in[] = "hello"; char out[6] = {0, 0, 0, 0, 0, 0}; boost::asio::streambuf s; s.sputn(in, sizeof(in)); s.sgetn(out, sizeof(in)); cout << out << endl << s.size() << endl; s.consume(1000); return 0; }
I'm using an asio::streambuf to read and write data to a socket. Despite my best efforts, I can't get the streambuf to throw an exception if I consume too much. I'm trying to get it to throw an exception so I can test an error case.
The documentation says streambuf::consume will throw an std::length error if the requested amount to read is greater than the input stream size (http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/reference/basic_str...).
It's a bug in the ducumentation. The function is implemented as follows: void consume(std::size_t n) { if (gptr() + n > pptr()) n = pptr() - gptr(); gbump(static_cast<int>(n)); } So it doesn't throw anything - it just wouldn't allow you to consume more data than available. Actually, it seems to be the correct and consistent behavior.
participants (2)
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Dylan Klomparens
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Igor R