etl/test/test_span_fixed_extent.cpp

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2020 John Wellbelove

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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******************************************************************************/

#include "unit_test_framework.h"

#include "etl/span.h"
#include "etl/array.h"
#include "etl/unaligned_type.h"

#include <array>
#include <vector>
#include <algorithm>
#include <iterator>
#if ETL_USING_CPP20
  #include <span>
#endif

namespace
{
  SUITE(test_span_fixed_extent)
  {
    static const size_t SIZE = 10UL;

    typedef etl::array<int, SIZE> EtlData;
    typedef std::array<int, SIZE> StlData;
    typedef std::vector<int> StlVData;

    typedef etl::span<int, 10U> View;
    typedef etl::span<int, 9U> SView;
    typedef etl::span<const int, 10U> CView;
    typedef etl::span<int, 0U> EView;

#if ETL_USING_CPP20
    using StdView = std::span<int, 10U>;
#endif

    EtlData etldata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    StlData stldata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    StlVData stlvdata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

    EtlData etldatasmaller = { 0, 1, 2, 3, 4, 5, 5, 7, 8, 9 };

    EtlData etloriginal = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    EtlData etlmodified = { 10, 10, 10, 10, 10, 10, 10, 10, 10, 10 };

    const EtlData cetldata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    const StlData cstldata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    const StlVData cstlvdata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

    int cdata[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    int* pcdata = cdata;

    const int ccdata[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    const int* pccdata = ccdata;

#if ETL_USING_CPP20
    //*************************************************************************
    TEST(test_construct_from_std_span)
    {
      StdView stdview(stldata);
      View view(stdview);

      CHECK_EQUAL(stdview.size(), view.size());
      CHECK_EQUAL(stdview.size(), view.size());

      bool isEqual = std::equal(view.begin(), view.end(), stdview.begin());
      CHECK(isEqual);
    }
#endif

    //*************************************************************************
    TEST(test_constructor_etl_array_1)
    {
      View view(etldata);

      CHECK_EQUAL(etldata.size(), view.size());
      CHECK_EQUAL(etldata.max_size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), etldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_etl_array_1_const)
    {
      CView view(cetldata);

      CHECK_EQUAL(cetldata.size(), view.size());
      CHECK_EQUAL(cetldata.max_size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), cetldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_etl_array_2)
    {
      View view(etldata.begin(), etldata.end());

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), etldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_etl_array_2_const)
    {
      CView view(cetldata.begin(), cetldata.end());

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), cetldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_stl_array_1)
    {
      View view(stldata);

      CHECK_EQUAL(stldata.size(), view.size());
      CHECK_EQUAL(stldata.max_size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), stldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_stl_array_1_const)
    {
      CView view(cstldata);

      CHECK_EQUAL(cstldata.size(), view.size());
      CHECK_EQUAL(cstldata.max_size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), cstldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_stl_array_2)
    {
      View view(stldata.begin(), stldata.end());

      CHECK_EQUAL(stldata.size(), view.size());
      CHECK_EQUAL(stldata.max_size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), stldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_stl_array_2_const)
    {
      CView view(cstldata.begin(), cstldata.end());

      CHECK_EQUAL(cstldata.size(), view.size());
      CHECK_EQUAL(cstldata.max_size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), cstldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_stl_vector_1)
    {
      View view(stlvdata);

      CHECK_EQUAL(stlvdata.size(), view.size());
      CHECK_EQUAL(stlvdata.size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), stlvdata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_stl_vector_1_const)
    {
      CView view(cstlvdata);

      CHECK_EQUAL(cstlvdata.size(), view.size());
      CHECK_EQUAL(cstlvdata.size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), cstlvdata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_c_array_1)
    {
      View view(pcdata, SIZE);

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), pcdata);
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_c_array_1_const)
    {
      CView view(pccdata, SIZE);

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), pccdata);
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_c_array_2)
    {
      View view(cdata);

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), cdata);
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_constructor_c_array_2_const)
    {
      CView view(ccdata);

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), ccdata);
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_implicit_constructor_c_array_2)
    {
      CView view(ccdata);

      CHECK_EQUAL(SIZE, view.size());
      CHECK_EQUAL(SIZE, view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), ccdata);
      CHECK(isEqual);
    }

#if ETL_USING_CPP17 && ETL_HAS_INITIALIZER_LIST && !defined(ETL_TEMPLATE_DEDUCTION_GUIDE_TESTS_DISABLED)
    //*************************************************************************
    TEST(test_cpp17_deduced_constructor)
    {
      etl::array data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

      etl::span span1{ data };
      etl::span span2{ data.begin(), data.end() };
      etl::span span3{ data.begin(), data.size() };
      etl::span span4{ span1 };

      int c_array[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::span span5{ c_array };

      bool isEqual = false;

      isEqual = std::equal(span1.begin(), span1.end(), data.begin());
      CHECK(isEqual);

      isEqual = std::equal(span2.begin(), span2.end(), data.begin());
      CHECK(isEqual);

      isEqual = std::equal(span3.begin(), span3.end(), data.begin());
      CHECK(isEqual);

      isEqual = std::equal(span4.begin(), span4.end(), data.begin());
      CHECK(isEqual);

      isEqual = std::equal(span5.begin(), span5.end(), c_array);
      CHECK(isEqual);
    }
#endif

    //*************************************************************************
    TEST(test_constructor_range)
    {
      View view(etldata.begin(), etldata.end());

      CHECK_EQUAL(etldata.size(), view.size());
      CHECK_EQUAL(etldata.size(), view.max_size());

      bool isEqual = std::equal(view.begin(), view.end(), etldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_copy_constructor_from_same_span_type)
    {
      etl::array<char, 10> data = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

      const etl::span<char, 10> view1(data.data(), data.data() + data.size());
      etl::span<char, 10> view2(view1);

      CHECK_EQUAL(data.size(), view1.size());
      CHECK_EQUAL(data.size(), view2.size());

      bool isEqual = std::equal(view1.begin(), view1.end(), view2.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_copy_constructor_from_different_span_type)
    {
      etl::array<char, 10> data = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

      const etl::span<char, 10> view1(data.data(), data.data() + data.size());
      etl::span<const char, 10> view2(view1);

      CHECK_EQUAL(data.size(), view1.size());
      CHECK_EQUAL(data.size(), view2.size());

      bool isEqual = std::equal(view1.begin(), view1.end(), view2.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_assign_from_span)
    {
      View view1(etldata);
      View view2 = view1;

      CView cview1(etldata);
      CView cview2 = view2;

      cview2 = cview1;

      CHECK_EQUAL(view1.size(), view2.size());
      CHECK_EQUAL(view1.max_size(), view2.max_size());

      CHECK_EQUAL(cview1.size(), cview2.size());
      CHECK_EQUAL(cview1.max_size(), cview2.max_size());

      bool isEqual;

      isEqual = std::equal(view1.begin(), view1.end(), view2.begin());
      CHECK(isEqual);

      isEqual = std::equal(cview1.begin(), cview1.end(), cview2.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_modify_range)
    {
      View view(etloriginal.begin(), etloriginal.end());

      CHECK_EQUAL(etloriginal.size(), view.size());
      CHECK_EQUAL(etloriginal.size(), view.max_size());

      std::fill(view.begin(), view.end(), 10);

      bool isEqual;

      isEqual = std::equal(etloriginal.begin(), etloriginal.end(), etlmodified.begin());
      CHECK(isEqual);

      isEqual = std::equal(etldata.begin(), etldata.end(), etlmodified.begin());
      CHECK(!isEqual);
    }

    //*************************************************************************
    TEST(test_begin_end)
    {
      View  view(etldata.begin(), etldata.end());
      CView cview(etldata.begin(), etldata.end());

      CHECK_EQUAL(etldata.cbegin(), view.cbegin());
      CHECK_EQUAL(etldata.begin(), view.begin());
      CHECK_EQUAL(etldata.begin(), cview.begin());

      CHECK_EQUAL(etldata.cend(), view.crbegin().base());
      CHECK_EQUAL(etldata.end(), view.rbegin().base());
      CHECK_EQUAL(etldata.end(), cview.rbegin().base());

      CHECK_EQUAL(etldata.cend(), view.cend());
      CHECK_EQUAL(etldata.end(), view.end());
      CHECK_EQUAL(etldata.end(), cview.end());

      CHECK_EQUAL(etldata.cbegin(), view.crend().base());
      CHECK_EQUAL(etldata.begin(), view.rend().base());
      CHECK_EQUAL(etldata.begin(), cview.rend().base());
    }

    //*************************************************************************
    TEST(test_front_back)
    {
      View  view(etldata.begin(), etldata.end());
      CView cview(etldata.begin(), etldata.end());

      CHECK_EQUAL(etldata.front(), view.front());
      CHECK_EQUAL(etldata.front(), cview.front());

      CHECK_EQUAL(etldata.back(), view.back());
      CHECK_EQUAL(etldata.back(), cview.back());

      // These should trigger static asserts
      // auto empty_view = view.subspan<0, 0>();
      // CHECK_THROW({ auto front = empty_view.front(); (void)front; }, etl::span_out_of_range);
      // CHECK_THROW({ auto back = empty_view.back(); (void)back; }, etl::span_out_of_range);

      // auto empty_cview = cview.subspan<0, 0>();
      // CHECK_THROW({ auto front = empty_cview.front(); (void)front; }, etl::span_out_of_range);
      // CHECK_THROW({ auto back = empty_cview.back(); (void)back; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_data)
    {
      View  view(etldata.begin(), etldata.end());
      CView cview(etldata.begin(), etldata.end());

      CHECK_EQUAL(etldata.data(), view.data());
      CHECK_EQUAL(etldata.data(), cview.data());
    }

    //*************************************************************************
    TEST(test_at)
    {
      View  view(etldata.begin(), etldata.end());
      CView cview(etldata.begin(), etldata.end());

      for (size_t i = 0UL; i < etldata.size(); ++i)
      {
        CHECK_EQUAL(etldata.at(i), view.at(i));
        CHECK_EQUAL(etldata.at(i), cview.at(i));
      }

      CHECK_THROW({ int d = view.at(view.size()); (void)d; }, etl::span_out_of_range);
      CHECK_THROW({ int d = cview.at(cview.size()); (void)d; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_index_operator)
    {
      View  view(etldata.begin(), etldata.end());
      CView cview(etldata.begin(), etldata.end());

      for (size_t i = 0UL; i < etldata.size(); ++i)
      {
        CHECK_EQUAL(etldata[i], view[i]);
        CHECK_EQUAL(etldata[i], cview[i]);
      }

      CHECK_THROW({ int d = view[view.size()]; (void)d; }, etl::span_out_of_range);
      CHECK_THROW({ int d = cview[cview.size()]; (void)d; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_assignment_operator)
    {
      View view(etldata);
      CView cview = view;

      CHECK_EQUAL(etldata.size(), cview.size());
      CHECK_EQUAL(etldata.max_size(), cview.max_size());

      bool isEqual = std::equal(cview.begin(), cview.end(), etldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_empty)
    {
      EView view2(etldata.begin(), etldata.begin());
      CHECK(view2.empty());
    }

    //*************************************************************************
    TEST(test_construction_from_mismatched_size)
    {
      CHECK_THROW((View(etldata.begin(), etldata.begin())),    etl::span_size_mismatch);
      CHECK_THROW((View(etldata.begin(), 1)),                  etl::span_size_mismatch);
      CHECK_THROW((View(etldata.begin(), etldata.size() - 1)), etl::span_size_mismatch);
      CHECK_THROW((View(etldata.begin(), etldata.size() + 1)), etl::span_size_mismatch);
    }

    //*************************************************************************
    TEST(test_size)
    {
      View view(etldata);

      CHECK_EQUAL(etldata.size(), view.size());
    }

    //*************************************************************************
    TEST(test_size_bytes)
    {
      View view(etldata);

      CHECK_EQUAL(etldata.size() * sizeof(EtlData::value_type), view.size_bytes());
    }

    //*************************************************************************
    TEST(test_swap)
    {
      View view1(etldata);
      View view2(etldatasmaller);

      std::swap(view1, view2);

      CHECK_EQUAL(etldata.size(), view1.size());
      CHECK_EQUAL(etldatasmaller.size(), view2.size());

      bool isEqual;

      isEqual = std::equal(view1.begin(), view1.end(), etldatasmaller.begin());
      CHECK(isEqual);

      isEqual = std::equal(view2.begin(), view2.end(), etldata.begin());
      CHECK(isEqual);
    }

    //*************************************************************************
    TEST(test_first)
    {
      std::vector<int> original = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      std::vector<int> first    = { 0, 1, 2, 3, 4, 5 };
      View view(original);
      CView cview(original);

      bool isEqual;

      auto result = view.first<6>();
      isEqual = std::equal(result.begin(), result.end(), first.begin());
      CHECK(isEqual);
      CHECK_EQUAL(first.size(), result.extent);
      CHECK_EQUAL(first.size(), result.size());

      auto cresult = cview.first<6>();
      isEqual = std::equal(cresult.begin(), cresult.end(), first.begin());
      CHECK(isEqual);
      CHECK_EQUAL(first.size(), cresult.extent);
      CHECK_EQUAL(first.size(), cresult.size());

      // These should trigger static asserts
      // CHECK_THROW({ auto result2 = view.first<11>(); (void)result2; }, etl::span_out_of_range);
      // CHECK_THROW({ auto cresult2 = cview.first<11>(); (void)cresult2; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_first_2)
    {
      std::vector<int> original = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      std::vector<int> first = { 0, 1, 2, 3, 4, 5 };
      View view(original);
      CView cview(original);

      bool isEqual;

      auto result = view.first(6);
      isEqual = std::equal(result.begin(), result.end(), first.begin());
      CHECK(isEqual);
      CHECK_EQUAL(first.size(), result.size());

      auto cresult = cview.first(6);
      isEqual = std::equal(cresult.begin(), cresult.end(), first.begin());
      CHECK(isEqual);
      CHECK_EQUAL(first.size(), cresult.size());

      CHECK_THROW({ auto result2 = view.first(11); (void)result2; }, etl::span_out_of_range);
      CHECK_THROW({ auto cresult2 = cview.first(11); (void)cresult2; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_last)
    {
      std::vector<int> original = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      std::vector<int> last     = { 4, 5, 6, 7, 8, 9 };
      View view(original);
      CView cview(original);

      bool isEqual;

      auto result = view.last<6>();
      isEqual = std::equal(result.begin(), result.end(), last.begin());
      CHECK(isEqual);
      CHECK_EQUAL(last.size(), result.extent);
      CHECK_EQUAL(last.size(), result.size());

      auto cresult = cview.last<6>();
      isEqual = std::equal(cresult.begin(), cresult.end(), last.begin());
      CHECK(isEqual);
      CHECK_EQUAL(last.size(), cresult.extent);
      CHECK_EQUAL(last.size(), cresult.size());

      //these should trigger static asserts
      // CHECK_THROW({ auto result2 = view.last<11>(); (void)result2; }, etl::span_out_of_range);
      // CHECK_THROW({ auto cresult2 = cview.last<11>(); (void)cresult2; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_last_2)
    {
      std::vector<int> original = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      std::vector<int> last = { 4, 5, 6, 7, 8, 9 };
      View view(original);
      CView cview(original);

      bool isEqual;

      auto result = view.last(6);
      isEqual = std::equal(result.begin(), result.end(), last.begin());
      CHECK(isEqual);
      CHECK_EQUAL(last.size(), result.size());

      auto cresult = cview.last(6);
      isEqual = std::equal(cresult.begin(), cresult.end(), last.begin());
      CHECK(isEqual);
      CHECK_EQUAL(last.size(), cresult.size());

      CHECK_THROW({ auto result2 = view.last(11); (void)result2; }, etl::span_out_of_range);
      CHECK_THROW({ auto cresult2 = cview.last(11); (void)cresult2; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_subspan)
    {
      std::vector<int> original = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      std::vector<int> sub1 = { 2, 3, 4, 5 };
      std::vector<int> sub2 = { 2, 3, 4, 5, 6, 7 };
      View view(original);
      CView cview(original);

      bool isEqual;

      auto span1 = view.subspan<2, 4>();
      isEqual = std::equal(span1.begin(), span1.end(), sub1.begin());
      CHECK(isEqual);
      CHECK_EQUAL(sub1.size(), span1.extent);
      CHECK_EQUAL(sub1.size(), span1.size());

      auto cspan1 = cview.subspan<2, 4>();
      isEqual = std::equal(cspan1.begin(), cspan1.end(), sub1.begin());
      CHECK(isEqual);
      CHECK_EQUAL(sub1.size(), cspan1.extent);
      CHECK_EQUAL(sub1.size(), cspan1.size());

      auto span2 = view.subspan<2>();
      isEqual = std::equal(sub2.begin(), sub2.end(), span2.begin());
      CHECK(isEqual);
      CHECK_EQUAL(span2.size(), span2.extent);

      auto cspan2 = cview.subspan<2>();
      isEqual = std::equal(sub2.begin(), sub2.end(), cspan2.begin());
      CHECK(isEqual);
      CHECK_EQUAL(original.size() - 2U, cspan2.extent);

      auto span3 = view.subspan(2, 4);
      isEqual = std::equal(sub1.begin(), sub1.end(), span3.begin());
      CHECK(isEqual);
      CHECK_EQUAL(etl::dynamic_extent, span3.extent);

      auto cspan3 = cview.subspan(2, 4);
      isEqual = std::equal(sub1.begin(), sub1.end(), cspan3.begin());
      CHECK(isEqual);
      CHECK_EQUAL(etl::dynamic_extent, cspan3.extent);

      auto span4 = view.subspan(2);
      isEqual = std::equal(sub2.begin(), sub2.end(), span4.begin());
      CHECK(isEqual);
      CHECK_EQUAL(etl::dynamic_extent, span4.extent);

      auto cspan4 = cview.subspan(2);
      isEqual = std::equal(sub2.begin(), sub2.end(), cspan4.begin());
      CHECK(isEqual);
      CHECK_EQUAL(etl::dynamic_extent, cspan4.extent);

      //these should trigger static asserts
      // CHECK_THROW({ auto span5 = view.subspan<11>(); (void)span5; }, etl::span_out_of_range);
      // CHECK_THROW({ auto cspan5 = cview.subspan<11>(); (void)cspan5; }, etl::span_out_of_range);

      // #define SPAN6_EXPR { auto span6 = view.subspan<2, 9>(); (void)span6; }
      // CHECK_THROW(SPAN6_EXPR, etl::span_out_of_range);
      // #define CSPAN6_EXPR { auto cspan6 = cview.subspan<2, 9>(); (void)cspan6; }
      // CHECK_THROW(CSPAN6_EXPR, etl::span_out_of_range);

      CHECK_THROW({ auto span7 = view.subspan(11); (void)span7; }, etl::span_out_of_range);
      CHECK_THROW({ auto cspan7 = cview.subspan(11); (void)cspan7; }, etl::span_out_of_range);

      CHECK_THROW({ auto span8 = view.subspan(2, 9); (void)span8; }, etl::span_out_of_range);
      CHECK_THROW({ auto cspan8 = cview.subspan(2, 9); (void)cspan8; }, etl::span_out_of_range);
    }

    //*************************************************************************
    TEST(test_hash)
    {
      View  view(etldata.begin(), etldata.end());
      CView cview(etldata.begin(), etldata.end());

      size_t hashdata = etl::private_hash::generic_hash<size_t>(reinterpret_cast<const uint8_t*>(etldata.data()),
                                                                reinterpret_cast<const uint8_t*>(etldata.data() + etldata.size()));

      size_t hashview  = etl::hash<View>()(view);
      size_t hashcview = etl::hash<CView>()(cview);

      CHECK_EQUAL(hashdata, hashview);
      CHECK_EQUAL(hashdata, hashcview);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST(test_template_deduction_guide_for_c_array)
    {
      int data[] = { 1, 2, 3, 4 };

      etl::span s = data;

      CHECK_EQUAL(ETL_OR_STD17::size(data), s.extent);
      CHECK_EQUAL(ETL_OR_STD17::size(data), s.size());
      CHECK((std::is_same_v<int, std::remove_reference_t<decltype(s.front())>>));
    }

#if ETL_USING_STL
    //*************************************************************************
    TEST(test_template_deduction_guide_for_std_array)
    {
      std::array<int, 4U> data = { 1, 2, 3, 4 };

      etl::span s = data;

      CHECK_EQUAL(ETL_OR_STD17::size(data), s.extent);
      CHECK_EQUAL(ETL_OR_STD17::size(data), s.size());
      CHECK((std::is_same_v<int, std::remove_reference_t<decltype(s.front())>>));
    }
#endif

    //*************************************************************************
    TEST(test_template_deduction_guide_for_etl_array)
    {
      etl::array<int, 4U> data = { 1, 2, 3, 4 };

      etl::span s = data;

      CHECK_EQUAL(ETL_OR_STD17::size(data), s.extent);
      CHECK_EQUAL(ETL_OR_STD17::size(data), s.size());
      CHECK((std::is_same_v<int, std::remove_reference_t<decltype(s.front())>>));
    }

    //*************************************************************************
    TEST(test_template_deduction_guide_for_iterators)
    {
      etl::array<int, 4U> data = { 1, 2, 3, 4 };

      etl::span s{ data.begin(), data.end() };

      CHECK_EQUAL(etl::dynamic_extent, s.extent);
      CHECK_EQUAL(4U, s.size());
      CHECK((std::is_same_v<int, std::remove_reference_t<decltype(s.front())>>));
    }

    //*************************************************************************
    TEST(test_template_deduction_guide_for_iterator_and_size)
    {
      etl::array<int, 4U> data = { 1, 2, 3, 4 };

      etl::span s{ data.begin(), data.size() };

      CHECK_EQUAL(etl::dynamic_extent, s.extent);
      CHECK_EQUAL(4U, s.size());
      CHECK((std::is_same_v<int, std::remove_reference_t<decltype(s.front())>>));
    }
#endif

    //*************************************************************************
    void f_issue_481(etl::span<const char, 10>)
    {
    }

    TEST(test_issue_481)
    {
      // Should compile.
      char c[10];
      f_issue_481(c);
    }

    //*************************************************************************
#include "etl/private/diagnostic_unused_function_push.h"

    struct C_issue_482 {};

    void f_issue_482(etl::span<char>)
    {
    }

    void f_issue_482(etl::span<C_issue_482>)
    {
    }

    TEST(test_issue_482)
    {
      etl::array<C_issue_482, 10> c;

      // Should compile without ambiguous function error.
      f_issue_482(c);
    }

    //*************************************************************************
    void f_issue_482_2(etl::span<char, 10>)
    {
    }

    void f_issue_482_2(etl::span<C_issue_482, 10>)
    {
    }

    TEST(test_issue_482_2)
    {
      etl::array<C_issue_482, 10> c;

      // Should compile without ambiguous function error.
      f_issue_482(c);
    }

    //*************************************************************************
    void f_issue_486(etl::span<const char, 11>)
    {
    }

    TEST(test_issue_486)
    {
      //std::array<char, 10> c;
      //etl::array<char, 10> c2;

      // Should not compile.
      //etl::span<char, 11> value(c);
      //etl::span<char, 11> value2(c2);

      // Should not compile.
      //f_issue_486(c);
      //f_issue_486(c2);
    }

    //*************************************************************************
    TEST(test_circular_iterator_pre_increment)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };

      View view{ data };

      View::circular_iterator sci = view.begin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i], *++sci);
      }
    }

    //*************************************************************************
    TEST(test_circular_iterator_pre_increment_for_subspan)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 3, 4, 5, 2, 3, 4, 5, 2, 3, 4, 5, 2, 3, 4, 5, 2, 3, 4, 5, 2 };

      View view{ data };
      etl::span<int, 4U> subspan = view.subspan<2, 4>();

      View::circular_iterator sci = subspan.begin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i], *++sci);
      }
    }

    //*************************************************************************
    TEST(test_circular_iterator_post_increment)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

      View view{ data };

      View::circular_iterator sci = view.begin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i % ETL_OR_STD17::size(expected)], *sci++);
      }
    }

    //*************************************************************************
    TEST(test_circular_iterator_post_increment_for_subspan)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 2, 3, 4, 5, 2, 3, 4, 5, 2, 3, 4, 5, 2, 3, 4, 5, 2, 3, 4, 5 };

      View view{ data };
      etl::span<int, 4U> subspan = view.subspan<2, 4>();

      View::circular_iterator sci = subspan.begin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i], *sci++);
      }
    }

    //*************************************************************************
    TEST(test_circular_reverse_iterator_pre_increment)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9 };

      View view{ data };

      View::reverse_circular_iterator sci = view.rbegin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i % ETL_OR_STD17::size(expected)], *++sci);
      }
    }

    //*************************************************************************
    TEST(test_circular_reverse_iterator_pre_increment_for_subspan)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 4, 3, 2, 5, 4, 3, 2, 5, 4, 3, 2, 5, 4, 3, 2, 5, 4, 3, 2, 5 };

      View view{ data };
      etl::span<int, 4U> subspan = view.subspan<2, 4>();

      etl::span<int, 10U>::reverse_circular_iterator sci = subspan.rbegin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i % ETL_OR_STD17::size(expected)], *++sci);
      }
    }

    //*************************************************************************
    TEST(test_circular_reverse_iterator_post_increment)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 };

      View view{ data };

      View::reverse_circular_iterator sci = view.rbegin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i % ETL_OR_STD17::size(expected)], *sci++);
      }
    }

    //*************************************************************************
    TEST(test_circular_reverse_iterator_post_increment_for_subspan)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 5, 4, 3, 2, 5, 4, 3, 2, 5, 4, 3, 2, 5, 4, 3, 2, 5, 4, 3, 2 };

      View view{ data };
      etl::span<int, 4U> subspan = view.subspan<2, 4>();

      View::reverse_circular_iterator sci = subspan.rbegin_circular();

      for (int i = 0; i < 20; ++i)
      {
        CHECK_EQUAL(expected[i % ETL_OR_STD17::size(expected)], *sci++);
      }
    }

    //*************************************************************************
    TEST(test_operator_plus_equals)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 20> expected{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

      View view{ data };

      for (int step = 1; step < 20; ++step)
      {
        View::circular_iterator sci = view.begin_circular();

        for (int i = 0; i < 20; i += step)
        {
          CHECK_EQUAL(expected[i % 10], *sci);
          sci += step;
        }
      }
    }

    //*************************************************************************
    TEST(test_operator_plus)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> expected{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

      View view{ data };

      for (int step = 1; step < 20; ++step)
      {
        View::circular_iterator sci = view.begin_circular();

        for (int i = 0; i < 20; i += step)
        {
          CHECK_EQUAL(expected[i % 10], *sci);
          sci = sci + step;
        }
      }
    }

    //*************************************************************************
    TEST(test_operator_minus_equals)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> expected{ 0, 9, 8, 7, 6, 5, 4, 3, 2, 1 };

      View view{ data };

      for (int step = 1; step < 20; ++step)
      {
        View::circular_iterator sci = view.begin_circular();

        for (int i = 0; i < 20; i += step)
        {
          CHECK_EQUAL(expected[i % 10], *sci);
          sci -= step;
        }
      }
    }

    //*************************************************************************
    TEST(test_operator_minus)
    {
      etl::array<int, 10> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> expected{ 0, 9, 8, 7, 6, 5, 4, 3, 2, 1 };

      View view{ data };

      for (int step = 1; step < 20; ++step)
      {
        View::circular_iterator sci = view.begin_circular();

        for (int i = 0; i < 20; i += step)
        {
          CHECK_EQUAL(expected[i % 10], *sci);
          sci = sci - step;
        }
      }
    }

    //*************************************************************************
    TEST(test_operator_equality)
    {
      etl::array<int, 10> data1{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data2{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data3{ 0, 1, 2, 3, 4, 4, 6, 7, 8, 9 };
      etl::array<int, 9>  data4{ 0, 1, 2, 3, 4, 5, 6, 7, 8 };

      View view1{ data1 };
      View view2{ data1 };
      View view3{ data2 };
      View view4{ data3 };
      SView view8{ data4 };

      CHECK_TRUE(etl::equal(view1, view2));
      CHECK_TRUE(etl::equal(view1, view3));
      CHECK_FALSE(etl::equal(view1, view4));
      CHECK_FALSE(etl::equal(view1, view8));

      CHECK_TRUE(view1 == view2);
      CHECK_FALSE(view1 == view3);
      CHECK_FALSE(view1 == view4);
      CHECK_FALSE(view1 == view8);
    }

    //*************************************************************************
    TEST(test_operator_equality_one_is_const)
    {
      etl::array<int, 10> data1{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data2{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data3{ 0, 1, 2, 3, 4, 4, 6, 7, 8, 9 };

      View view1{ data1 };
      CView view2{ data1 };
      CView view3{ data2 };
      CView view4{ data3 };

      CHECK_TRUE(etl::equal(view1, view2));
      CHECK_TRUE(etl::equal(view1, view3));
      CHECK_FALSE(etl::equal(view1, view4));

      CHECK_TRUE(view1 == view2);
      CHECK_FALSE(view1 == view3);
      CHECK_FALSE(view1 == view4);
    }

    //*************************************************************************
    TEST(test_operator_not_equal)
    {
      etl::array<int, 10> data1{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data2{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data3{ 0, 1, 2, 3, 4, 4, 6, 7, 8, 9 };

      View view1{ data1 };
      View view2{ data1 };
      View view3{ data2 };
      View view4{ data3 };

      CHECK_TRUE(etl::equal(view1, view2));
      CHECK_TRUE(etl::equal(view1, view3));
      CHECK_FALSE(etl::equal(view1, view4));

      CHECK_FALSE(view1 != view2);
      CHECK_TRUE(view1 != view3);
      CHECK_TRUE(view1 != view4);
    }

    //*************************************************************************
    TEST(test_operator_not_equal_one_is_const)
    {
      etl::array<int, 10> data1{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data2{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
      etl::array<int, 10> data3{ 0, 1, 2, 3, 4, 4, 6, 7, 8, 9 };

      View view1{ data1 };
      CView view2{ data1 };
      CView view3{ data2 };
      CView view4{ data3 };

      CHECK_TRUE(etl::equal(view1, view2));
      CHECK_TRUE(etl::equal(view1, view3));
      CHECK_FALSE(etl::equal(view1, view4));

      CHECK_FALSE(view1 != view2);
      CHECK_TRUE(view1 != view3);
      CHECK_TRUE(view1 != view4);
    }

    //*************************************************************************
    TEST(test_convert_span_any_to_span_byte)
    {
      float data[2]{3.141592f, 2.71828f};
      const float const_data[2]{3.141592f, 2.71828f};

#if ETL_USING_CPP17
      auto const const_bytes    = etl::as_bytes(etl::span{ const_data });
      auto const writable_bytes = etl::as_writable_bytes(etl::span{ data });
#else
      auto const const_bytes    = etl::as_bytes(etl::span<const float, 2>(const_data));
      auto const writable_bytes = etl::as_writable_bytes(etl::span<float, 2>(data));
#endif

      CHECK_EQUAL(const_bytes.size(),    sizeof(data));
      CHECK_EQUAL(writable_bytes.size(), sizeof(data));

      etl::byte* pdata = reinterpret_cast<etl::byte*>(data);

      // Test the reading of bytes.
      for (size_t i = 0; i < sizeof(data); ++i)
      {
        CHECK_EQUAL(int(pdata[i]), int(const_bytes[i]));
        CHECK_EQUAL(int(pdata[i]), int(writable_bytes[i]));
      }

      // Test writing of bytes.
      for (size_t i = 0; i < writable_bytes.size(); ++i)
      {
        writable_bytes[i] = ~writable_bytes[i];
        CHECK_EQUAL(int(pdata[i]), int(writable_bytes[i]));
      }
    }

    //*************************************************************************
    TEST(test_make_span_c_array)
    {
      {
        auto s = etl::make_span(cdata);

        CHECK_EQUAL(s.size(), 10);
        View view(etldata);
        CHECK_TRUE(etl::equal(s, view));
      }
      {
        auto s = etl::make_span(ccdata);

        CHECK_EQUAL(s.size(), 10);
        View view(etldata);
        CHECK_TRUE(etl::equal(s, view));
      }
    }

    //*************************************************************************
    TEST(test_span_issue_1050_questions_on_span_constructors)
    {
      int arr[5]{};
      etl::span<int, 5> span1(arr);
      etl::span<int, 5> span2(span1);
      //etl::span<int, 10> span3(span1); // This line should fail to compile.
    }

    //*************************************************************************
    TEST(test_reinterpret_as)
    {
      uint8_t data[] = { 0x01, 0x02, 0x03, 0x04, 0x05 };
      etl::span<uint8_t, 5> data0 = data;

      auto data1 = data0.reinterpret_as<etl::be_uint16_t>();

      CHECK_EQUAL(data1.size(), 2);
      CHECK(data1[0] == 0x102);
      CHECK(data1[1] == 0x304);
    }

    //*************************************************************************
    TEST(test_reinterpret_as_aligned)
    {
      uint32_t data[] = { 0x01020304, 0x020406080, 0x03400560};
      etl::span<uint32_t, 3> data0 = data;
      CHECK_EQUAL(data0.size(), 3);

      auto data1 = data0.reinterpret_as<uint8_t>();
      CHECK_EQUAL(data1.size(), 12);

      auto data2 = data1.subspan<2>().reinterpret_as<uint16_t>();
      CHECK_EQUAL(data2.size(), 5);

      CHECK_THROW(data2 = data1.subspan<1>().reinterpret_as<uint16_t>(), etl::span_alignment_exception);
    }

    //*************************************************************************
    TEST(test_copy)
    {
      uint8_t src[] = { 0x01, 0x02, 0x03, 0x04, 0x05 };
      uint8_t dst[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
      {
        etl::span<uint8_t, 5> data0 = src;
        etl::span<uint8_t, 6> data1 = dst;

        CHECK_EQUAL(etl::copy(data0, data1), true);
        CHECK(std::equal(data0.begin(), data0.end(), data1.begin()));
      }
      {
        etl::span<uint8_t, 5> data0 = src;
        etl::span<uint8_t, 5> data1(&dst[1], 5);

        CHECK_EQUAL(etl::copy(data0, data1), true);
        CHECK(std::equal(data0.begin(), data0.end(), data1.begin()));
      }

      {
        etl::span<uint8_t, 5> data0 = src;
        etl::span<uint8_t, 4> data1(&dst[2], 4);

        CHECK_EQUAL(etl::copy(data0, data1), false);
      }
      {
        etl::span<uint8_t, 0> data0(&src[0], 0);
        etl::span<uint8_t, 6> data1 = dst;

        CHECK_EQUAL(etl::copy(data0, data1), true);
      }
      {
        etl::span<uint8_t, 5> data0 = src;
        etl::span<uint8_t, 5> data1 = src;

        CHECK_EQUAL(etl::copy(data0, data1), true);
      }
    }

    //*************************************************************************
    TEST(test_dynamic_span_to_fixed_span)
    {
      int data[5] = { 0, 1, 2, 3, 4 };
      etl::span<int> sp1(data);

      using span_4 = etl::span<int, 4>;
      using span_5 = etl::span<int, 5>;
      using span_8 = etl::span<int, 8>;

      CHECK_NO_THROW({ span_5 sp2(sp1); });
      CHECK_THROW({ span_4 sp3(sp1); }, etl::span_size_mismatch);
      CHECK_THROW({ span_8 sp4(sp1); }, etl::span_size_mismatch);
    }

#include "etl/private/diagnostic_pop.h"

    //*************************************************************************
    TEST(test_not_constructible_from_rvalue_container)
    {
#if ETL_USING_CPP17
      CHECK(!(etl::is_constructible_v<View,  StlVData&&>));
      CHECK(!(etl::is_constructible_v<CView, StlVData&&>));

      CHECK(!(etl::is_constructible_v<View,  EtlData&&>));
      CHECK(!(etl::is_constructible_v<View,  StlData&&>));
#else
      CHECK(!(etl::is_constructible<View,  StlVData&&>::value));
      CHECK(!(etl::is_constructible<CView, StlVData&&>::value));

      CHECK(!(etl::is_constructible<View,  EtlData&&>::value));
      CHECK(!(etl::is_constructible<View,  StlData&&>::value));
#endif
    }
  }
}