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.
  //
  //===----------------------------------------------------------------------===//
  
  
  // <string_view>
  
  // constexpr basic_string_view(const _CharT* _s)
  //    : __data (_s), __size(_Traits::length(_s)) {}
  
  
  #include <experimental/string_view>
  #include <string>
  #include <cassert>
  
  #include "constexpr_char_traits.hpp"
  
  template<typename CharT>
  size_t StrLen ( const CharT *s ) {
      size_t retVal = 0;
      while ( *s != 0 ) { ++retVal; ++s; }
      return retVal;
      }
  
  template<typename CharT>
  void test ( const CharT *s ) {
      std::experimental::basic_string_view<CharT> sv1 ( s );
      assert ( sv1.size() == StrLen( s ));
      assert ( sv1.data() == s );
      }
  
  
  int main () {
  
      test ( "QBCDE" );
      test ( "A" );
      test ( "" );
      
      test ( L"QBCDE" );
      test ( L"A" );
      test ( L"" );
  
  #if __cplusplus >= 201103L
      test ( u"QBCDE" );
      test ( u"A" );
      test ( u"" );
  
      test ( U"QBCDE" );
      test ( U"A" );
      test ( U"" );
  #endif
  
  #if _LIBCPP_STD_VER > 11
      {
      constexpr std::experimental::basic_string_view<char, constexpr_char_traits<char>> sv1 ( "ABCDE" );
      static_assert ( sv1.size() == 5, "");
      }
  #endif
  }
  