libcxx/test/std/input.output/iostream.format/input.streams/istream.unformatted/read.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 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx10.{{9|10|11|12|13|14}}
  10
  11 // <istream>
  12
  13 // basic_istream<charT,traits>& read(char_type* s, streamsize n);
  14
  15 #include <istream>
  16 #include <cassert>
  17 #include "test_macros.h"
  18
  19 template <class CharT>
  20 struct testbuf
  21     : public std::basic_streambuf<CharT>
  22 {
  23     typedef std::basic_string<CharT> string_type;
  24     typedef std::basic_streambuf<CharT> base;
  25 private:
  26     string_type str_;
  27 public:
  28
  29     testbuf() {}
  30     testbuf(const string_type& str)
  31         : str_(str)
  32     {
  33         base::setg(const_cast<CharT*>(str_.data()),
  34                    const_cast<CharT*>(str_.data()),
  35                    const_cast<CharT*>(str_.data()) + str_.size());
  36     }
  37
  38     CharT* eback() const {return base::eback();}
  39     CharT* gptr() const {return base::gptr();}
  40     CharT* egptr() const {return base::egptr();}
  41 };
  42
  43 int main(int, char**)
  44 {
  45     {
  46         testbuf<char> sb(" 123456789");
  47         std::istream is(&sb);
  48         char s[5];
  49         is.read(s, 5);
  50         assert(!is.eof());
  51         assert(!is.fail());
  52         assert(std::string(s, 5) == " 1234");
  53         assert(is.gcount() == 5);
  54         is.read(s, 5);
  55         assert(!is.eof());
  56         assert(!is.fail());
  57         assert(std::string(s, 5) == "56789");
  58         assert(is.gcount() == 5);
  59         is.read(s, 5);
  60         assert( is.eof());
  61         assert( is.fail());
  62         assert(is.gcount() == 0);
  63     }
  64 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  65     {
  66         testbuf<wchar_t> sb(L" 123456789");
  67         std::wistream is(&sb);
  68         wchar_t s[5];
  69         is.read(s, 5);
  70         assert(!is.eof());
  71         assert(!is.fail());
  72         assert(std::wstring(s, 5) == L" 1234");
  73         assert(is.gcount() == 5);
  74         is.read(s, 5);
  75         assert(!is.eof());
  76         assert(!is.fail());
  77         assert(std::wstring(s, 5) == L"56789");
  78         assert(is.gcount() == 5);
  79         is.read(s, 5);
  80         assert( is.eof());
  81         assert( is.fail());
  82         assert(is.gcount() == 0);
  83     }
  84 #endif
  85 #ifndef TEST_HAS_NO_EXCEPTIONS
  86     {
  87         testbuf<char> sb;
  88         std::basic_istream<char> is(&sb);
  89         is.exceptions(std::ios_base::eofbit);
  90         char s[10];
  91         bool threw = false;
  92         try {
  93             is.read(s, 5);
  94         } catch (std::ios_base::failure&) {
  95             threw = true;
  96         }
  97         assert(threw);
  98         assert(!is.bad());
  99         assert( is.eof());
 100         assert( is.fail());
 101     }
 102 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 103     {
 104         testbuf<wchar_t> sb;
 105         std::basic_istream<wchar_t> is(&sb);
 106         is.exceptions(std::ios_base::eofbit);
 107         wchar_t s[10];
 108         bool threw = false;
 109         try {
 110             is.read(s, 5);
 111         } catch (std::ios_base::failure&) {
 112             threw = true;
 113         }
 114         assert(threw);
 115         assert(!is.bad());
 116         assert( is.eof());
 117         assert( is.fail());
 118     }
 119 #endif
 120 #endif // TEST_HAS_NO_EXCEPTIONS
 121
 122     return 0;
 123 }