| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <ostream> |
| |
| // template <class charT, class traits = char_traits<charT> > |
| // class basic_ostream; |
| |
| // basic_ostream<charT,traits>& seekp(off_type off, ios_base::seekdir dir); |
| |
| #include <ostream> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| int seekoff_called = 0; |
| |
| template <class CharT> |
| struct testbuf |
| : public std::basic_streambuf<CharT> |
| { |
| typedef std::basic_streambuf<CharT> base; |
| testbuf() {} |
| |
| protected: |
| |
| typename base::pos_type |
| seekoff(typename base::off_type off, std::ios_base::seekdir way, |
| std::ios_base::openmode which) |
| { |
| ++seekoff_called; |
| assert(way == std::ios_base::beg); |
| assert(which == std::ios_base::out); |
| return off; |
| } |
| }; |
| |
| int main(int, char**) |
| { |
| { |
| seekoff_called = 0; |
| std::ostream os((std::streambuf*)0); |
| assert(&os.seekp(5, std::ios_base::beg) == &os); |
| assert(seekoff_called == 0); |
| } |
| { |
| seekoff_called = 0; |
| testbuf<char> sb; |
| std::ostream os(&sb); |
| assert(&os.seekp(10, std::ios_base::beg) == &os); |
| assert(seekoff_called == 1); |
| assert(os.good()); |
| assert(&os.seekp(-1, std::ios_base::beg) == &os); |
| assert(seekoff_called == 2); |
| assert(os.fail()); |
| } |
| { // See https://llvm.org/PR21361 |
| seekoff_called = 0; |
| testbuf<char> sb; |
| std::ostream os(&sb); |
| os.setstate(std::ios_base::eofbit); |
| assert(&os.seekp(10, std::ios_base::beg) == &os); |
| assert(seekoff_called == 1); |
| assert(os.rdstate() == std::ios_base::eofbit); |
| } |
| |
| return 0; |
| } |