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 // <istream> 11 12 // int sync(); 13 14 #include <istream> 15 #include <cassert> 16 17 int sync_called = 0; 18 19 template <class CharT> 20 struct testbuf 21 : public std::basic_streambuf<CharT> 22 { 23 typedef std::basic_string<CharT> string_type; 24 typedef std::basic_streambuf<CharT> base; 25 private: 26 string_type str_; 27 public: 28 testbuftestbuf29 testbuf() {} testbuftestbuf30 testbuf(const string_type& str) 31 : str_(str) 32 { 33 base::setg(const_cast<CharT*>(str_.data()), 34 const_cast<CharT*>(str_.data()), 35 const_cast<CharT*>(str_.data()) + str_.size()); 36 } 37 ebacktestbuf38 CharT* eback() const {return base::eback();} gptrtestbuf39 CharT* gptr() const {return base::gptr();} egptrtestbuf40 CharT* egptr() const {return base::egptr();} 41 42 protected: synctestbuf43 int sync() 44 { 45 ++sync_called; 46 return 5; 47 } 48 }; 49 main()50int main() 51 { 52 { 53 testbuf<char> sb(" 123456789"); 54 std::istream is(&sb); 55 assert(is.sync() == 0); 56 assert(sync_called == 1); 57 } 58 { 59 testbuf<wchar_t> sb(L" 123456789"); 60 std::wistream is(&sb); 61 assert(is.sync() == 0); 62 assert(sync_called == 2); 63 } 64 } 65