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=macosx10.12 11 // XFAIL: with_system_cxx_lib=macosx10.11 12 // XFAIL: with_system_cxx_lib=macosx10.10 13 // XFAIL: with_system_cxx_lib=macosx10.9 14 // XFAIL: with_system_cxx_lib=macosx10.7 15 // XFAIL: with_system_cxx_lib=macosx10.8 16 17 // <istream> 18 19 // basic_istream<charT,traits>& seekg(off_type off, ios_base::seekdir dir); 20 21 #include <istream> 22 #include <cassert> 23 24 int seekoff_called = 0; 25 26 template <class CharT> 27 struct testbuf 28 : public std::basic_streambuf<CharT> 29 { 30 typedef std::basic_string<CharT> string_type; 31 typedef std::basic_streambuf<CharT> base; 32 private: 33 string_type str_; 34 public: 35 36 testbuf() {} 37 testbuf(const string_type& str) 38 : str_(str) 39 { 40 base::setg(const_cast<CharT*>(str_.data()), 41 const_cast<CharT*>(str_.data()), 42 const_cast<CharT*>(str_.data()) + str_.size()); 43 } 44 45 CharT* eback() const {return base::eback();} 46 CharT* gptr() const {return base::gptr();} 47 CharT* egptr() const {return base::egptr();} 48 protected: 49 typename base::pos_type seekoff(typename base::off_type off, 50 std::ios_base::seekdir, 51 std::ios_base::openmode which) 52 { 53 assert(which == std::ios_base::in); 54 ++seekoff_called; 55 return off; 56 } 57 }; 58 59 int main() 60 { 61 { 62 testbuf<char> sb(" 123456789"); 63 std::istream is(&sb); 64 is.seekg(5, std::ios_base::cur); 65 assert(is.good()); 66 assert(seekoff_called == 1); 67 is.seekg(-1, std::ios_base::beg); 68 assert(is.fail()); 69 assert(seekoff_called == 2); 70 } 71 { 72 testbuf<wchar_t> sb(L" 123456789"); 73 std::wistream is(&sb); 74 is.seekg(5, std::ios_base::cur); 75 assert(is.good()); 76 assert(seekoff_called == 3); 77 is.seekg(-1, std::ios_base::beg); 78 assert(is.fail()); 79 assert(seekoff_called == 4); 80 } 81 { 82 testbuf<char> sb(" 123456789"); 83 std::istream is(&sb); 84 is.setstate(std::ios_base::eofbit); 85 assert(is.eof()); 86 is.seekg(5, std::ios_base::beg); 87 assert(is.good()); 88 assert(!is.eof()); 89 } 90 } 91
