| 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-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | // <fstream> |
| 10 | |
| 11 | // int_type pbackfail(int_type c = traits::eof()); |
| 12 | |
| 13 | // FILE_DEPENDENCIES: underflow.dat |
| 14 | |
| 15 | #include <fstream> |
| 16 | #include <cassert> |
| 17 | |
| 18 | #include "test_macros.h" |
| 19 | |
| 20 | template <class CharT> |
| 21 | struct test_buf |
| 22 | : public std::basic_filebuf<CharT> |
| 23 | { |
| 24 | typedef std::basic_filebuf<CharT> base; |
| 25 | typedef typename base::char_type char_type; |
| 26 | typedef typename base::int_type int_type; |
| 27 | typedef typename base::traits_type traits_type; |
| 28 | |
| 29 | char_type* eback() const {return base::eback();} |
| 30 | char_type* gptr() const {return base::gptr();} |
| 31 | char_type* egptr() const {return base::egptr();} |
| 32 | void gbump(int n) {base::gbump(n);} |
| 33 | |
| 34 | virtual int_type pbackfail(int_type c = traits_type::eof()) {return base::pbackfail(c);} |
| 35 | }; |
| 36 | |
| 37 | int main(int, char**) |
| 38 | { |
| 39 | { |
| 40 | test_buf<char> f; |
| 41 | assert(f.open("underflow.dat", std::ios_base::in) != 0); |
| 42 | assert(f.is_open()); |
| 43 | assert(f.sbumpc() == '1'); |
| 44 | assert(f.sgetc() == '2'); |
| 45 | typename test_buf<char>::int_type pbackResult = f.pbackfail(c: 'a'); |
| 46 | LIBCPP_ASSERT(pbackResult == -1); |
| 47 | if (pbackResult != -1) { |
| 48 | assert(f.sbumpc() == 'a'); |
| 49 | assert(f.sgetc() == '2'); |
| 50 | } |
| 51 | } |
| 52 | { |
| 53 | test_buf<char> f; |
| 54 | assert(f.open("underflow.dat", std::ios_base::in | std::ios_base::out) != 0); |
| 55 | assert(f.is_open()); |
| 56 | assert(f.sbumpc() == '1'); |
| 57 | assert(f.sgetc() == '2'); |
| 58 | typename test_buf<char>::int_type pbackResult = f.pbackfail(c: 'a'); |
| 59 | LIBCPP_ASSERT(pbackResult == 'a'); |
| 60 | if (pbackResult != -1) { |
| 61 | assert(f.sbumpc() == 'a'); |
| 62 | assert(f.sgetc() == '2'); |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | return 0; |
| 67 | } |
| 68 |