libcxx/test/std/input.output/stream.buffers/streambuf/streambuf.members/streambuf.pub.get/in_avail.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 // <streambuf>
  10
  11 // template <class charT, class traits = char_traits<charT> >
  12 // class basic_streambuf;
  13
  14 // streamsize in_avail();
  15
  16 #include <streambuf>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20
  21 int showmanyc_called = 0;
  22
  23 template <class CharT>
  24 struct test
  25     : public std::basic_streambuf<CharT>
  26 {
  27     typedef std::basic_streambuf<CharT> base;
  28
  29     test() {}
  30
  31     void setg(CharT* gbeg, CharT* gnext, CharT* gend)
  32     {
  33         base::setg(gbeg, gnext, gend);
  34     }
  35 protected:
  36     std::streamsize showmanyc()
  37     {
  38         ++showmanyc_called;
  39         return 5;
  40     }
  41 };
  42
  43 int main(int, char**)
  44 {
  45     {
  46         test<char> t;
  47         assert(t.in_avail() == 5);
  48         assert(showmanyc_called == 1);
  49         char in[5];
  50         t.setg(in, in+2, in+5);
  51         assert(t.in_avail() == 3);
  52     }
  53
  54   return 0;
  55 }