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; 14 15 // basic_ostream<charT,traits>& seekp(off_type off, ios_base::seekdir dir); 16 17 #include <ostream> 18 #include <cassert> 19 20 int seekoff_called = 0; 21 22 template <class CharT> 23 struct testbuf 24 : public std::basic_streambuf<CharT> 25 { 26 typedef std::basic_streambuf<CharT> base; 27 testbuf() {} 28 29 protected: 30 31 typename base::pos_type 32 seekoff(typename base::off_type off, std::ios_base::seekdir way, 33 std::ios_base::openmode which) 34 { 35 ++seekoff_called; 36 assert(way == std::ios_base::beg); 37 assert(which == std::ios_base::out); 38 return off; 39 } 40 }; 41 42 int main() 43 { 44 { 45 seekoff_called = 0; 46 std::ostream os((std::streambuf*)0); 47 assert(&os.seekp(5, std::ios_base::beg) == &os); 48 assert(seekoff_called == 0); 49 } 50 { 51 seekoff_called = 0; 52 testbuf<char> sb; 53 std::ostream os(&sb); 54 assert(&os.seekp(10, std::ios_base::beg) == &os); 55 assert(seekoff_called == 1); 56 assert(os.good()); 57 assert(&os.seekp(-1, std::ios_base::beg) == &os); 58 assert(seekoff_called == 2); 59 assert(os.fail()); 60 } 61 { // See https://llvm.org/bugs/show_bug.cgi?id=21361 62 seekoff_called = 0; 63 testbuf<char> sb; 64 std::ostream os(&sb); 65 os.setstate(std::ios_base::eofbit); 66 assert(&os.seekp(10, std::ios_base::beg) == &os); 67 assert(seekoff_called == 1); 68 assert(os.rdstate() == std::ios_base::eofbit); 69 } 70 } 71
