libcxx/test/std/input.output/iostream.format/input.streams/istream.unformatted/ignore.pass.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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // Requires 396145d in the built library.
  10 // XFAIL: using-built-library-before-llvm-9
  11
  12 // <istream>
  13
  14 // basic_istream<charT,traits>&
  15 //    ignore(streamsize n = 1, int_type delim = traits::eof());
  16
  17 #include <istream>
  18 #include <cassert>
  19 #include <streambuf>
  20
  21 #include "test_macros.h"
  22
  23 template <class CharT>
  24 struct testbuf
  25     : public std::basic_streambuf<CharT>
  26 {
  27     typedef std::basic_string<CharT> string_type;
  28     typedef std::basic_streambuf<CharT> base;
  29 private:
  30     string_type str_;
  31 public:
  32
  33     testbuf() {}
  34     testbuf(const string_type& str)
  35         : str_(str)
  36     {
  37         base::setg(const_cast<CharT*>(str_.data()),
  38                    const_cast<CharT*>(str_.data()),
  39                    const_cast<CharT*>(str_.data()) + str_.size());
  40     }
  41
  42     CharT* eback() const {return base::eback();}
  43     CharT* gptr() const {return base::gptr();}
  44     CharT* egptr() const {return base::egptr();}
  45 };
  46
  47 int main(int, char**)
  48 {
  49     {
  50         testbuf<char> sb(" 1\n2345\n6");
  51         std::istream is(&sb);
  52         is.ignore();
  53         assert(!is.eof());
  54         assert(!is.fail());
  55         assert(is.gcount() == 1);
  56         is.ignore(5, '\n');
  57         assert(!is.eof());
  58         assert(!is.fail());
  59         assert(is.gcount() == 2);
  60         is.ignore(15);
  61         assert( is.eof());
  62         assert(!is.fail());
  63         assert(is.gcount() == 6);
  64     }
  65 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  66     {
  67         testbuf<wchar_t> sb(L" 1\n2345\n6");
  68         std::wistream is(&sb);
  69         is.ignore();
  70         assert(!is.eof());
  71         assert(!is.fail());
  72         assert(is.gcount() == 1);
  73         is.ignore(5, '\n');
  74         assert(!is.eof());
  75         assert(!is.fail());
  76         assert(is.gcount() == 2);
  77         is.ignore(15);
  78         assert( is.eof());
  79         assert(!is.fail());
  80         assert(is.gcount() == 6);
  81     }
  82 #endif
  83 #ifndef TEST_HAS_NO_EXCEPTIONS
  84     {
  85         testbuf<char> sb(" ");
  86         std::basic_istream<char> is(&sb);
  87         is.exceptions(std::ios_base::eofbit);
  88         bool threw = false;
  89         try {
  90             is.ignore(5);
  91         } catch (std::ios_base::failure&) {
  92             threw = true;
  93         }
  94         assert(threw);
  95         assert(!is.bad());
  96         assert( is.eof());
  97         assert(!is.fail());
  98     }
  99 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 100     {
 101         testbuf<wchar_t> sb(L" ");
 102         std::basic_istream<wchar_t> is(&sb);
 103         is.exceptions(std::ios_base::eofbit);
 104         bool threw = false;
 105         try {
 106             is.ignore(5);
 107         } catch (std::ios_base::failure&) {
 108             threw = true;
 109         }
 110         assert(threw);
 111         assert(!is.bad());
 112         assert( is.eof());
 113         assert(!is.fail());
 114     }
 115 #endif
 116 #endif // TEST_HAS_NO_EXCEPTIONS
 117
 118     return 0;
 119 }