#include <ostream>
#include <cassert>
int sync_called = 0;
template <class CharT>
struct testbuf1
: public std::basic_streambuf<CharT>
{
testbuf1() {}
protected:
int virtual sync()
{
++sync_called;
return 1;
}
};
int main()
{
{
std::ostream os((std::streambuf*)0);
std::ostream::sentry s(os);
assert(!bool(s));
}
assert(sync_called == 0);
{
testbuf1<char> sb;
std::ostream os(&sb);
std::ostream::sentry s(os);
assert(bool(s));
}
assert(sync_called == 0);
{
testbuf1<char> sb;
std::ostream os(&sb);
std::ostream::sentry s(os);
assert(bool(s));
unitbuf(os);
}
assert(sync_called == 1);
{
testbuf1<char> sb;
std::ostream os(&sb);
try
{
std::ostream::sentry s(os);
assert(bool(s));
unitbuf(os);
throw 1;
}
catch (...)
{
}
assert(sync_called == 1);
}
}