1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <ostream> 11 12 // template <class charT, class traits = char_traits<charT> > 13 // class basic_ostream::sentry; 14 15 // explicit sentry(basic_ostream<charT,traits>& os); 16 17 #include <ostream> 18 #include <cassert> 19 20 int sync_called = 0; 21 22 template <class CharT> 23 struct testbuf1 24 : public std::basic_streambuf<CharT> 25 { testbuf1testbuf126 testbuf1() {} 27 28 protected: 29 synctestbuf130 int virtual sync() 31 { 32 ++sync_called; 33 return 1; 34 } 35 }; 36 main()37int main() 38 { 39 { 40 std::ostream os((std::streambuf*)0); 41 std::ostream::sentry s(os); 42 assert(!bool(s)); 43 } 44 { 45 testbuf1<char> sb; 46 std::ostream os(&sb); 47 std::ostream::sentry s(os); 48 assert(bool(s)); 49 } 50 { 51 testbuf1<char> sb; 52 std::ostream os(&sb); 53 testbuf1<char> sb2; 54 std::ostream os2(&sb2); 55 os.tie(&os2); 56 assert(sync_called == 0); 57 std::ostream::sentry s(os); 58 assert(bool(s)); 59 assert(sync_called == 1); 60 } 61 } 62