Cheesy thread-synchronized std::cout output.

syncout.hpp

////////////////////////////////////////////////////////////////////////////////
// Class to substitute for cout to get synchronization of output.
// Usage: syncout << "foo " << 0xff << syncendl;
using namespace std;
class syncostringstream : public ostringstream {};
#define syncout syncostringstream()
ostream &syncendl(ostream &ostr)
{
    if(auto *sostr = dynamic_cast< syncostringstream* >( &ostr ))
    {
        static mutex m;
        unique_lock< mutex > lock(m);
        ostr << endl;
        cout << sostr->str();
    }
    else
        cerr << "ostream type not an syncostringstream, cannot synchronize output" << endl;
    return ostr;
}