text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  // <codecvt>
  
  // template <class Elem, unsigned long Maxcode = 0x10ffff,
  //           codecvt_mode Mode = (codecvt_mode)0>
  // class codecvt_utf8
  //     : public codecvt<Elem, char, mbstate_t>
  // {
  //     // unspecified
  // };
  
  // int length(stateT& state, const externT* from, const externT* from_end,
  //            size_t max) const;
  
  #include <codecvt>
  #include <cassert>
  
  int main(int, char**)
  {
      {
          typedef std::codecvt_utf8<wchar_t> C;
          C c;
          char n[4] = {char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+4, 1);
          assert(r == 4);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 3);
  
          n[0] = char(0xD1);
          n[1] = char(0x93);
          r = c.length(m, n, n+2, 3);
          assert(r == 2);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<wchar_t, 0x1000> C;
          C c;
          char n[4] = {char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+4, 1);
          assert(r == 0);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 0);
  
          n[0] = char(0xD1);
          n[1] = char(0x93);
          r = c.length(m, n, n+2, 3);
          assert(r == 2);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<wchar_t, 0xFFFFFFFF, std::consume_header> C;
          C c;
          char n[7] = {char(0xEF), char(0xBB), char(0xBF), char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+7, 1);
          assert(r == 7);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 3);
  
          n[0] = char(0xEF);
          n[1] = char(0xBB);
          n[2] = char(0xBF);
          n[3] = char(0xD1);
          n[4] = char(0x93);
          r = c.length(m, n, n+5, 3);
          assert(r == 5);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<char32_t> C;
          C c;
          char n[4] = {char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+4, 1);
          assert(r == 4);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 3);
  
          n[0] = char(0xD1);
          n[1] = char(0x93);
          r = c.length(m, n, n+2, 3);
          assert(r == 2);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<char32_t, 0x1000> C;
          C c;
          char n[4] = {char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+4, 1);
          assert(r == 0);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 0);
  
          n[0] = char(0xD1);
          n[1] = char(0x93);
          r = c.length(m, n, n+2, 3);
          assert(r == 2);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<char32_t, 0xFFFFFFFF, std::consume_header> C;
          C c;
          char n[7] = {char(0xEF), char(0xBB), char(0xBF), char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+7, 1);
          assert(r == 7);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 3);
  
          n[0] = char(0xEF);
          n[1] = char(0xBB);
          n[2] = char(0xBF);
          n[3] = char(0xD1);
          n[4] = char(0x93);
          r = c.length(m, n, n+5, 3);
          assert(r == 5);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<char16_t> C;
          C c;
          char n[4] = {char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+4, 1);
          assert(r == 0);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 3);
  
          n[0] = char(0xD1);
          n[1] = char(0x93);
          r = c.length(m, n, n+2, 3);
          assert(r == 2);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<char16_t, 0x1000> C;
          C c;
          char n[4] = {char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+4, 1);
          assert(r == 0);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 0);
  
          n[0] = char(0xD1);
          n[1] = char(0x93);
          r = c.length(m, n, n+2, 3);
          assert(r == 2);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
      {
          typedef std::codecvt_utf8<char16_t, 0xFFFFFFFF, std::consume_header> C;
          C c;
          char n[7] = {char(0xEF), char(0xBB), char(0xBF), char(0xF1), char(0x80), char(0x80), char(0x83)};
          std::mbstate_t m;
          int r = c.length(m, n, n+7, 1);
          assert(r == 3);
  
          n[0] = char(0xE1);
          n[1] = char(0x80);
          n[2] = char(0x85);
          r = c.length(m, n, n+3, 2);
          assert(r == 3);
  
          n[0] = char(0xEF);
          n[1] = char(0xBB);
          n[2] = char(0xBF);
          n[3] = char(0xD1);
          n[4] = char(0x93);
          r = c.length(m, n, n+5, 3);
          assert(r == 5);
  
          n[0] = char(0x56);
          r = c.length(m, n, n+1, 3);
          assert(r == 1);
      }
  
    return 0;
  }
  