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
  //
  //===----------------------------------------------------------------------===//
  
  // <forward_list>
  
  // void splice_after(const_iterator p, forward_list&& x,
  //                   const_iterator first, const_iterator last);
  
  #include <stddef.h>
  #include <forward_list.hxx>
  #include <cassert.hxx>
  #include <iterator.hxx>
  
  #include "test_macros.h"
  #include "min_allocator.h"
  
  typedef ptrdiff_t T;
  const T t1[] = {0, 1, 2, 3, 4, 5, 6, 7};
  const T t2[] = {10, 11, 12, 13, 14, 15};
  const ptrdiff_t size_t1 = std::end(t1) - std::begin(t1);
  const ptrdiff_t size_t2 = std::end(t2) - std::begin(t2);
  
  template <class C>
  void
  testd(const C& c, ptrdiff_t p, ptrdiff_t f, ptrdiff_t l)
  {
      typename C::const_iterator i = c.begin();
      ptrdiff_t n1 = 0;
      for (; n1 < p; ++n1, ++i)
          assert(*i == t1[n1]);
      for (ptrdiff_t n2 = f; n2 < l-1; ++n2, ++i)
          assert(*i == t2[n2]);
      for (; n1 < size_t1; ++n1, ++i)
          assert(*i == t1[n1]);
      assert(distance(c.begin(), c.end()) == size_t1 + (l > f+1 ? l-1-f : 0));
  }
  
  template <class C>
  void
  tests(const C& c, ptrdiff_t p, ptrdiff_t f, ptrdiff_t l)
  {
      typename C::const_iterator i = c.begin();
      ptrdiff_t n = 0;
      ptrdiff_t d = l > f+1 ? l-1-f : 0;
      if (d == 0 || p == f)
      {
          for (n = 0; n < size_t1; ++n, ++i)
              assert(*i == t1[n]);
      }
      else if (p < f)
      {
          for (n = 0; n < p; ++n, ++i)
              assert(*i == t1[n]);
          for (n = f; n < l-1; ++n, ++i)
              assert(*i == t1[n]);
          for (n = p; n < f; ++n, ++i)
              assert(*i == t1[n]);
          for (n = l-1; n < size_t1; ++n, ++i)
              assert(*i == t1[n]);
      }
      else // p > f
      {
          for (n = 0; n < f; ++n, ++i)
              assert(*i == t1[n]);
          for (n = l-1; n < p; ++n, ++i)
              assert(*i == t1[n]);
          for (n = f; n < l-1; ++n, ++i)
              assert(*i == t1[n]);
          for (n = p; n < size_t1; ++n, ++i)
              assert(*i == t1[n]);
      }
      assert(distance(c.begin(), c.end()) == size_t1);
  }
  
  int main(int, char**)
  {
      {
      // splicing different containers
      typedef std::forward_list<T> C;
      for (ptrdiff_t f = 0; f <= size_t2+1; ++f)
      {
          for (ptrdiff_t l = f; l <= size_t2+1; ++l)
          {
              for (ptrdiff_t p = 0; p <= size_t1; ++p)
              {
                  C c1(std::begin(t1), std::end(t1));
                  C c2(std::begin(t2), std::end(t2));
  
                  c1.splice_after(next(c1.cbefore_begin(), p), std::move(c2),
                        next(c2.cbefore_begin(), f), next(c2.cbefore_begin(), l));
                  testd(c1, p, f, l);
              }
          }
      }
  
      // splicing within same container
      for (ptrdiff_t f = 0; f <= size_t1+1; ++f)
      {
          for (ptrdiff_t l = f; l <= size_t1; ++l)
          {
              for (ptrdiff_t p = 0; p <= f; ++p)
              {
                  C c1(std::begin(t1), std::end(t1));
  
                  c1.splice_after(next(c1.cbefore_begin(), p), std::move(c1),
                        next(c1.cbefore_begin(), f), next(c1.cbefore_begin(), l));
                  tests(c1, p, f, l);
              }
              for (ptrdiff_t p = l; p <= size_t1; ++p)
              {
                  C c1(std::begin(t1), std::end(t1));
  
                  c1.splice_after(next(c1.cbefore_begin(), p), std::move(c1),
                        next(c1.cbefore_begin(), f), next(c1.cbefore_begin(), l));
                  tests(c1, p, f, l);
              }
          }
      }
      }
  #if TEST_STD_VER >= 11
      {
      // splicing different containers
      typedef std::forward_list<T, min_allocator<T>> C;
      for (ptrdiff_t f = 0; f <= size_t2+1; ++f)
      {
          for (ptrdiff_t l = f; l <= size_t2+1; ++l)
          {
              for (ptrdiff_t p = 0; p <= size_t1; ++p)
              {
                  C c1(std::begin(t1), std::end(t1));
                  C c2(std::begin(t2), std::end(t2));
  
                  c1.splice_after(next(c1.cbefore_begin(), p), std::move(c2),
                        next(c2.cbefore_begin(), f), next(c2.cbefore_begin(), l));
                  testd(c1, p, f, l);
              }
          }
      }
  
      // splicing within same container
      for (ptrdiff_t f = 0; f <= size_t1+1; ++f)
      {
          for (ptrdiff_t l = f; l <= size_t1; ++l)
          {
              for (ptrdiff_t p = 0; p <= f; ++p)
              {
                  C c1(std::begin(t1), std::end(t1));
  
                  c1.splice_after(next(c1.cbefore_begin(), p), std::move(c1),
                        next(c1.cbefore_begin(), f), next(c1.cbefore_begin(), l));
                  tests(c1, p, f, l);
              }
              for (ptrdiff_t p = l; p <= size_t1; ++p)
              {
                  C c1(std::begin(t1), std::end(t1));
  
                  c1.splice_after(next(c1.cbefore_begin(), p), std::move(c1),
                        next(c1.cbefore_begin(), f), next(c1.cbefore_begin(), l));
                  tests(c1, p, f, l);
              }
          }
      }
      }
  #endif
  
    return 0;
  }
  