libcxx/test/std/input.output/iostream.format/input.streams/istream.unformatted/sync.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 // <istream>
  10
  11 // int sync();
  12
  13 #include <istream>
  14 #include <cassert>
  15
  16 #include "test_macros.h"
  17
  18 int sync_called = 0;
  19
  20 template <class CharT>
  21 struct testbuf
  22     : public std::basic_streambuf<CharT>
  23 {
  24     typedef std::basic_string<CharT> string_type;
  25     typedef std::basic_streambuf<CharT> base;
  26 private:
  27     string_type str_;
  28 public:
  29
  30     testbuf() {}
  31     testbuf(const string_type& str)
  32         : str_(str)
  33     {
  34         base::setg(const_cast<CharT*>(str_.data()),
  35                    const_cast<CharT*>(str_.data()),
  36                    const_cast<CharT*>(str_.data()) + str_.size());
  37     }
  38
  39     CharT* eback() const {return base::eback();}
  40     CharT* gptr() const {return base::gptr();}
  41     CharT* egptr() const {return base::egptr();}
  42
  43 protected:
  44     int sync()
  45     {
  46         ++sync_called;
  47         return 5;
  48     }
  49 };
  50
  51 #ifndef TEST_HAS_NO_EXCEPTIONS
  52 struct testbuf_exception { };
  53
  54 template <class CharT>
  55 struct throwing_testbuf
  56     : public std::basic_streambuf<CharT>
  57 {
  58     typedef std::basic_string<CharT> string_type;
  59     typedef std::basic_streambuf<CharT> base;
  60 private:
  61     string_type str_;
  62 public:
  63
  64     throwing_testbuf() {}
  65     throwing_testbuf(const string_type& str)
  66         : str_(str)
  67     {
  68         base::setg(const_cast<CharT*>(str_.data()),
  69                    const_cast<CharT*>(str_.data()),
  70                    const_cast<CharT*>(str_.data()) + str_.size());
  71     }
  72
  73     CharT* eback() const {return base::eback();}
  74     CharT* gptr() const {return base::gptr();}
  75     CharT* egptr() const {return base::egptr();}
  76
  77 protected:
  78     virtual int sync()
  79     {
  80         throw testbuf_exception();
  81         return 5;
  82     }
  83 };
  84 #endif // TEST_HAS_NO_EXCEPTIONS
  85
  86 int main(int, char**)
  87 {
  88     {
  89         testbuf<char> sb(" 123456789");
  90         std::istream is(&sb);
  91         assert(is.sync() == 0);
  92         assert(sync_called == 1);
  93     }
  94 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  95     {
  96         testbuf<wchar_t> sb(L" 123456789");
  97         std::wistream is(&sb);
  98         assert(is.sync() == 0);
  99         assert(sync_called == 2);
 100     }
 101 #endif
 102 #ifndef TEST_HAS_NO_EXCEPTIONS
 103     {
 104         throwing_testbuf<char> sb(" 123456789");
 105         std::basic_istream<char> is(&sb);
 106         is.exceptions(std::ios_base::badbit);
 107         bool threw = false;
 108         try {
 109             is.sync();
 110         } catch (testbuf_exception const&) {
 111             threw = true;
 112         }
 113         assert( is.bad());
 114         assert(!is.eof());
 115         assert( is.fail());
 116         assert(threw);
 117     }
 118 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 119     {
 120         throwing_testbuf<wchar_t> sb(L" 123456789");
 121         std::basic_istream<wchar_t> is(&sb);
 122         is.exceptions(std::ios_base::badbit);
 123         bool threw = false;
 124         try {
 125             is.sync();
 126         } catch (testbuf_exception const&) {
 127             threw = true;
 128         }
 129         assert( is.bad());
 130         assert(!is.eof());
 131         assert( is.fail());
 132         assert(threw);
 133     }
 134 #endif
 135 #endif // TEST_HAS_NO_EXCEPTIONS
 136
 137     return 0;
 138 }