libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/default.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 // <sstream>
  10
  11 // template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
  12 // class basic_stringbuf
  13
  14 // explicit basic_stringbuf(ios_base::openmode which = ios_base::in | ios_base::out); // before C++20
  15 // basic_stringbuf() : basic_stringbuf(ios_base::in | ios_base::out) {}               // C++20
  16 // explicit basic_stringbuf(ios_base::openmode which);                                // C++20
  17
  18 // XFAIL: FROZEN-CXX03-HEADERS-FIXME
  19
  20 #include <sstream>
  21 #include <cassert>
  22
  23 #include "test_macros.h"
  24 #if TEST_STD_VER >= 11
  25 #include "test_convertible.h"
  26 #endif
  27
  28 template<typename CharT>
  29 struct testbuf
  30     : std::basic_stringbuf<CharT>
  31 {
  32     void check()
  33     {
  34       // LWG2995
  35       //   It is implementation-defined whether the sequence pointers (eback(),
  36       //   gptr(), egptr(), pbase(), pptr(), epptr()) are initialized to null
  37       //   pointers.
  38       // This tests the libc++ specific implementation.
  39       LIBCPP_ASSERT(this->eback() != nullptr);
  40       LIBCPP_ASSERT(this->gptr() != nullptr);
  41       LIBCPP_ASSERT(this->egptr() != nullptr);
  42       LIBCPP_ASSERT(this->pbase() != nullptr);
  43       LIBCPP_ASSERT(this->pptr() != nullptr);
  44       LIBCPP_ASSERT(this->epptr() != nullptr);
  45       assert(this->str().empty());
  46     }
  47 };
  48
  49 int main(int, char**)
  50 {
  51     {
  52         std::stringbuf buf;
  53         assert(buf.str() == "");
  54     }
  55     {
  56         testbuf<char> buf;
  57         buf.check();
  58     }
  59 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  60     {
  61         std::wstringbuf buf;
  62         assert(buf.str() == L"");
  63     }
  64     {
  65         testbuf<wchar_t> buf;
  66         buf.check();
  67     }
  68 #endif
  69
  70 #if TEST_STD_VER >= 11
  71     {
  72       typedef std::stringbuf B;
  73       static_assert(test_convertible<B>(), "");
  74       static_assert(!test_convertible<B, std::ios_base::openmode>(), "");
  75     }
  76 #endif
  77
  78     return 0;
  79 }