libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/underflow.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 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
  10
  11 // <strstream>
  12
  13 // class strstreambuf
  14
  15 // int_type underflow();
  16
  17 #include <strstream>
  18 #include <cassert>
  19
  20 #include "test_macros.h"
  21
  22 struct test
  23     : public std::strstreambuf
  24 {
  25     typedef std::strstreambuf base;
  26     test(char* gnext_arg, std::streamsize n, char* pbeg_arg = 0)
  27         : base(gnext_arg, n, pbeg_arg) {}
  28     test(const char* gnext_arg, std::streamsize n)
  29         : base(gnext_arg, n) {}
  30
  31     base::int_type underflow() {return base::underflow();}
  32 };
  33
  34 int main(int, char**)
  35 {
  36     {
  37         char buf[10] = "123";
  38         test sb(buf, 0, buf + 3);
  39         assert(sb.underflow() == '1');
  40         assert(sb.underflow() == '1');
  41         assert(sb.snextc() == '2');
  42         assert(sb.underflow() == '2');
  43         assert(sb.underflow() == '2');
  44         assert(sb.snextc() == '3');
  45         assert(sb.underflow() == '3');
  46         assert(sb.underflow() == '3');
  47         assert(sb.snextc() == EOF);
  48         assert(sb.underflow() == EOF);
  49         assert(sb.underflow() == EOF);
  50         sb.sputc('4');
  51         assert(sb.underflow() == '4');
  52         assert(sb.underflow() == '4');
  53     }
  54
  55   return 0;
  56 }