72 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// basic_ostream<charT,traits>& seekp(pos_type pos);15 16#include <ostream>17#include <cassert>18 19#include "test_macros.h"20 21int seekpos_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 seekpos(typename base::pos_type sp, std::ios_base::openmode which)34 {35 ++seekpos_called;36 assert(which == std::ios_base::out);37 return sp;38 }39};40 41int main(int, char**)42{43 {44 seekpos_called = 0;45 std::ostream os((std::streambuf*)0);46 assert(&os.seekp(5) == &os);47 assert(seekpos_called == 0);48 }49 {50 seekpos_called = 0;51 testbuf<char> sb;52 std::ostream os(&sb);53 assert(&os.seekp(10) == &os);54 assert(seekpos_called == 1);55 assert(os.good());56 assert(&os.seekp(-1) == &os);57 assert(seekpos_called == 2);58 assert(os.fail());59 }60 { // See https://llvm.org/PR2136161 seekpos_called = 0;62 testbuf<char> sb;63 std::ostream os(&sb);64 os.setstate(std::ios_base::eofbit);65 assert(&os.seekp(10) == &os);66 assert(seekpos_called == 1);67 assert(os.rdstate() == std::ios_base::eofbit);68 }69 70 return 0;71}72