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 // XFAIL: with_system_cxx_lib=macosx10.7 11 // XFAIL: with_system_cxx_lib=macosx10.8 12 13 // <istream> 14 15 // basic_istream<charT,traits>& seekg(pos_type pos); 16 17 #include <istream> 18 #include <cassert> 19 20 template <class CharT> 21 struct testbuf 22 : public std::basic_streambuf<CharT> 23 { 24 typedef std::basic_string<CharT> string_type; 25 typedef std::basic_streambuf<CharT> base; 26 private: 27 string_type str_; 28 public: 29 30 testbuf() {} 31 testbuf(const string_type& str) 32 : str_(str) 33 { 34 base::setg(const_cast<CharT*>(str_.data()), 35 const_cast<CharT*>(str_.data()), 36 const_cast<CharT*>(str_.data()) + str_.size()); 37 } 38 39 CharT* eback() const {return base::eback();} 40 CharT* gptr() const {return base::gptr();} 41 CharT* egptr() const {return base::egptr();} 42 protected: 43 typename base::pos_type seekpos(typename base::pos_type sp, 44 std::ios_base::openmode which) 45 { 46 assert(which == std::ios_base::in); 47 return sp; 48 } 49 }; 50 51 int main() 52 { 53 { 54 testbuf<char> sb(" 123456789"); 55 std::istream is(&sb); 56 is.seekg(5); 57 assert(is.good()); 58 is.seekg(-1); 59 assert(is.fail()); 60 } 61 { 62 testbuf<wchar_t> sb(L" 123456789"); 63 std::wistream is(&sb); 64 is.seekg(5); 65 assert(is.good()); 66 is.seekg(-1); 67 assert(is.fail()); 68 } 69 { 70 testbuf<char> sb(" 123456789"); 71 std::istream is(&sb); 72 is.setstate(std::ios_base::eofbit); 73 assert(is.eof()); 74 is.seekg(5); 75 assert(is.good()); 76 assert(!is.eof()); 77 } 78 } 79
