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// basic_ostream& flush();15 16#include <ostream>17#include <cassert>18 19#include "test_macros.h"20 21int sync_called = 0;22 23template <class CharT>24class testbuf25 : public std::basic_streambuf<CharT>26{27public:28 testbuf()29 {30 }31 32protected:33 34 virtual int35 sync()36 {37 if (sync_called++ == 1)38 return -1;39 return 0;40 }41};42 43int main(int, char**)44{45 {46 testbuf<char> sb;47 std::ostream os(&sb);48 os.flush();49 assert(os.good());50 assert(sync_called == 1);51 os.flush();52 assert(os.bad());53 assert(sync_called == 2);54 }55 56 return 0;57}58