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(pos_type pos); 16 17 #include <ostream> 18 #include <cassert> 19 20 int seekpos_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 seekpos(typename base::pos_type sp, std::ios_base::openmode which) 33 { 34 ++seekpos_called; 35 assert(which == std::ios_base::out); 36 return sp; 37 } 38 }; 39 40 int main() 41 { 42 { 43 seekpos_called = 0; 44 std::ostream os((std::streambuf*)0); 45 assert(&os.seekp(5) == &os); 46 assert(seekpos_called == 0); 47 } 48 { 49 seekpos_called = 0; 50 testbuf<char> sb; 51 std::ostream os(&sb); 52 assert(&os.seekp(10) == &os); 53 assert(seekpos_called == 1); 54 assert(os.good()); 55 assert(&os.seekp(-1) == &os); 56 assert(seekpos_called == 2); 57 assert(os.fail()); 58 } 59 { // See https://llvm.org/bugs/show_bug.cgi?id=21361 60 seekpos_called = 0; 61 testbuf<char> sb; 62 std::ostream os(&sb); 63 os.setstate(std::ios_base::eofbit); 64 assert(&os.seekp(10) == &os); 65 assert(seekpos_called == 1); 66 assert(os.rdstate() == std::ios_base::eofbit); 67 } 68 } 69
