58 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// <ostream>10 11// template <class charT, class traits = char_traits<charT> >12// class basic_ostream;13 14// pos_type tellp();15 16#include <ostream>17#include <cassert>18 19#include "test_macros.h"20 21int seekoff_called = 0;22 23template <class CharT>24struct testbuf25 : public std::basic_streambuf<CharT>26{27 typedef std::basic_streambuf<CharT> base;28 testbuf() {}29 30protected:31 32 typename base::pos_type33 seekoff(typename base::off_type off, std::ios_base::seekdir way, std::ios_base::openmode which)34 {35 assert(off == 0);36 assert(way == std::ios_base::cur);37 assert(which == std::ios_base::out);38 ++seekoff_called;39 return 10;40 }41};42 43int main(int, char**)44{45 {46 std::ostream os((std::streambuf*)0);47 assert(os.tellp() == -1);48 }49 {50 testbuf<char> sb;51 std::ostream os(&sb);52 assert(os.tellp() == 10);53 assert(seekoff_called == 1);54 }55 56 return 0;57}58