text: 
  //===----------------------------------------------------------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is dual licensed under the MIT and the University of Illinois Open
  // Source Licenses. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // <unordered_map> feature macros
  
  /*  Constant                                    Value
      __cpp_lib_allocator_traits_is_always_equal  201411L
      __cpp_lib_erase_if                          201811L
      __cpp_lib_node_extract                      201606L
      __cpp_lib_nonmember_container_access        201411L
      __cpp_lib_unordered_map_try_emplace         201411L
  
  */
  
  #include <unordered_map>
  #include <cassert>
  #include "test_macros.h"
  
  int main()
  {
  //  ensure that the macros that are supposed to be defined in <unordered_map> are defined.
  
  #if TEST_STD_VER > 17
  # if !defined(__cpp_lib_erase_if)  
    LIBCPP_STATIC_ASSERT(false, "__cpp_lib_erase_if is not defined");
  # else
  #  if __cpp_lib_erase_if < 201811L
  #   error "__cpp_lib_erase_if has an invalid value"
  #  endif
  # endif
  #endif
  
  
  /*
  #if !defined(__cpp_lib_fooby)
  # error "__cpp_lib_fooby is not defined"
  #elif __cpp_lib_fooby < 201606L
  # error "__cpp_lib_fooby has an invalid value"
  #endif
  */
  }
  