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

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

Copyright(c) 2014 jwellbelove

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******************************************************************************/

#include "UnitTest++.h"

#include "algorithm.h"
#include "container.h"

#include <vector>
#include <list>
#include <algorithm>
#include <functional>
#include <numeric>

namespace
{
  typedef std::vector<int> Data;
  Data data = { 2, 1, 4, 3, 6, 5, 8, 7, 10, 9 };

  SUITE(test_algorithm)
  {
    //=========================================================================
    TEST(minmax_element)
    {
      std::pair<Data::iterator, Data::iterator> expected = std::minmax_element(data.begin(), data.end());
      std::pair<Data::iterator, Data::iterator> result   = etl::minmax_element(data.begin(), data.end());
      CHECK_EQUAL(std::distance(data.begin(), expected.first), std::distance(data.begin(), result.first));
      CHECK_EQUAL(std::distance(data.begin(), expected.second), std::distance(data.begin(), result.second));
    }

    //=========================================================================
    TEST(minmax_element_compare)
    {
      std::pair<Data::iterator, Data::iterator> expected = std::minmax_element(data.begin(), data.end(), std::greater<int>());
      std::pair<Data::iterator, Data::iterator> result   = etl::minmax_element(data.begin(), data.end(), std::greater<int>());
      CHECK_EQUAL(std::distance(data.begin(), expected.first),  std::distance(data.begin(), result.first));
      CHECK_EQUAL(std::distance(data.begin(), expected.second), std::distance(data.begin(), result.second));
    }

    //=========================================================================
    TEST(minmax)
    {
      int a = 1;
      int b = 2;

      std::pair<int, int> expected = std::minmax(a, b);
      std::pair<int, int> result   = etl::minmax(a, b);
      CHECK_EQUAL(expected.first,  result.first);
      CHECK_EQUAL(expected.second, result.second);

      result   = etl::minmax(b, a);
      expected = std::minmax(b, a);
      CHECK_EQUAL(expected.first, result.first);
      CHECK_EQUAL(expected.second, result.second);
    }

    //=========================================================================
    TEST(minmax_compare)
    {
      int a = 1;
      int b = 2;

      std::pair<int, int> expected = std::minmax(a, b, std::greater<int>());
      std::pair<int, int> result   = etl::minmax(a, b, std::greater<int>());
      CHECK_EQUAL(expected.first, result.first);
      CHECK_EQUAL(expected.second, result.second);

      result   = etl::minmax(b, a, std::greater<int>());
      expected = std::minmax(b, a, std::greater<int>());
      CHECK_EQUAL(expected.first, result.first);
      CHECK_EQUAL(expected.second, result.second);
    }

    //=========================================================================
    TEST(is_sorted_until)
    {
      int data[] = { 1, 2, 3, 4, 6, 5, 7, 8, 9, 10 };

      int* p1 = std::is_sorted_until(std::begin(data), std::end(data));
      int* p2 = etl::is_sorted_until(std::begin(data), std::end(data));
      CHECK_EQUAL(std::distance(std::begin(data), p1), std::distance(std::begin(data), p2));
    }

    //=========================================================================
    TEST(is_sorted_until_compare)
    {
      int data[] = { 10, 9, 8, 7, 5, 6, 4, 3, 4, 2, 1 };

      int* p1 = std::is_sorted_until(std::begin(data), std::end(data), std::greater<int>());
      int* p2 = etl::is_sorted_until(std::begin(data), std::end(data), std::greater<int>());
      CHECK_EQUAL(std::distance(etl::begin(data), p1), std::distance(std::begin(data), p2));
    }

    //=========================================================================
    TEST(is_sorted)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

      bool is_sorted = etl::is_sorted(std::begin(data1), std::end(data1));
      CHECK(is_sorted);

      int data2[] = { 1, 2, 3, 4, 6, 5, 7, 8 , 9, 10};

      is_sorted = etl::is_sorted(std::begin(data2), std::end(data2));
      CHECK(!is_sorted);
    }

    //=========================================================================
    TEST(is_sorted_compare)
    {
      int data1[] = { 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 };

      bool is_sorted = etl::is_sorted(std::begin(data1), std::end(data1), std::greater<int>());
      CHECK(is_sorted);

      int data2[] = { 10, 9, 8, 7, 5, 6, 4, 3, 2, 1 };

      is_sorted = etl::is_sorted(std::begin(data2), std::end(data2), std::greater<int>());
      CHECK(!is_sorted);
    }

    //=========================================================================
    TEST(copy_4_parameter_random_iterator)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int data2[] = { 1, 2, 3, 4, 5 };

      int out1[10];
      int out2[5];

      int check1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int check2[] = { 1, 2, 3, 4, 5 };
      int check3[] = { 1, 2, 3, 4, 5, 0, 0, 0, 0, 0 };

      int* result;

      // Same size.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy(std::begin(data1), std::end(data1), std::begin(out1), std::end(out1));
      CHECK_EQUAL(std::end(out1), result);
      bool is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check1));
      CHECK(is_same);

      // Destination smaller.
      std::fill(std::begin(out2), std::end(out2), 0);
      result = etl::copy(std::begin(data1), std::end(data1), std::begin(out2), std::end(out2));
      CHECK_EQUAL(std::end(out2), result);
      is_same = std::equal(std::begin(out2), std::end(out2), std::begin(check2));
      CHECK(is_same);

      // Source smaller.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy(std::begin(data2), std::end(data2), std::begin(out1), std::end(out1));
      CHECK_EQUAL(std::begin(out1) + 5, result);
      is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_4_parameter_non_random_iterator)
    {
      std::list<int> data1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      std::list<int> data2 = { 1, 2, 3, 4, 5 };

      int out1[10];
      int out2[5];

      int check1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int check2[] = { 1, 2, 3, 4, 5 };
      int check3[] = { 1, 2, 3, 4, 5, 0, 0, 0, 0, 0 };

      int* result;

      // Same size.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy(std::begin(data1), std::end(data1), std::begin(out1), std::end(out1));
      CHECK_EQUAL(std::end(out1), result);
      bool is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check1));
      CHECK(is_same);

      // Destination smaller.
      std::fill(std::begin(out2), std::end(out2), 0);
      result = etl::copy(std::begin(data1), std::end(data1), std::begin(out2), std::end(out2));
      CHECK_EQUAL(std::end(out2), result);
      is_same = std::equal(std::begin(out2), std::end(out2), std::begin(check2));
      CHECK(is_same);

      // Source smaller.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy(std::begin(data2), std::end(data2), std::begin(out1), std::end(out1));
      CHECK_EQUAL(std::begin(out1) + 5, result);
      is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_n_random_iterator)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int data2[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int data3[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

      int* result;

      std::copy_n(std::begin(data1), 4, std::begin(data2));
      result = etl::copy_n(std::begin(data1), 4, std::begin(data3));

      CHECK_EQUAL(std::begin(data3) + 4, result);

      bool is_same = std::equal(std::begin(data2), std::end(data2), std::begin(data3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_n_non_random_iterator)
    {
      std::list<int> data1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int data2[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int data3[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

      int* result;

      std::copy_n(std::begin(data1), 4, std::begin(data2));
      result = etl::copy_n(std::begin(data1), 4, std::begin(data3));

      CHECK_EQUAL(std::begin(data3) + 4, result);

      bool is_same = std::equal(std::begin(data2), std::end(data2), std::begin(data3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_n_4_parameter)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

      int out1[10];
      int out2[5];

      int check1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int check2[] = { 1, 2, 3, 4, 5 };
      int check3[] = { 1, 2, 3, 4, 5, 0, 0, 0, 0, 0 };

      int* result;

      // Same size.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy_n(std::begin(data1), 10, std::begin(out1), std::end(out1));
      CHECK_EQUAL(std::end(out1), result);
      bool is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check1));
      CHECK(is_same);

      // Destination smaller.
      std::fill(std::begin(out2), std::end(out2), 0);
      result = etl::copy_n(std::begin(data1), 10, std::begin(out2), std::end(out2));
      CHECK_EQUAL(std::end(out2), result);
      is_same = std::equal(std::begin(out2), std::end(out2), std::begin(check2));
      CHECK(is_same);

      // Source smaller.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy_n(std::begin(data1), 5, std::begin(out1), std::end(out1));
      CHECK_EQUAL(std::begin(out1) + 5, result);
      is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_2n_4_parameter)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

      int out1[10];
      int out2[5];

      int check1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
      int check2[] = { 1, 2, 3, 4, 5 };
      int check3[] = { 1, 2, 3, 4, 5, 0, 0, 0, 0, 0 };

      int* result;

      // Same size.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy_n(std::begin(data1), 10, std::begin(out1), 10);
      CHECK_EQUAL(std::end(out1), result);
      bool is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check1));
      CHECK(is_same);

      // Destination smaller.
      std::fill(std::begin(out2), std::end(out2), 0);
      result = etl::copy_n(std::begin(data1), 10, std::begin(out2), 5);
      CHECK_EQUAL(std::end(out2), result);
      is_same = std::equal(std::begin(out2), std::end(out2), std::begin(check2));
      CHECK(is_same);

      // Source smaller.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy_n(std::begin(data1), 5, std::begin(out1), 10);
      CHECK_EQUAL(std::begin(out1) + 5, result);
      is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_if)
    {
      int data1[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int data2[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int data3[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

      // Copy everything less than 5.
      std::copy_if(std::begin(data1), std::end(data1), std::begin(data2), std::bind2nd(std::less<int>(), 5));
      etl::copy_if(std::begin(data1), std::end(data1), std::begin(data3), std::bind2nd(std::less<int>(), 5));

      bool is_same = std::equal(std::begin(data2), std::end(data2), std::begin(data3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_n_if)
    {
      int data1[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int data2[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int data3[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

      // Copy everything less than 5.
      int *pout = data2;
      for (int* pin = std::begin(data1); pin != std::begin(data1) + 6; ++pin)
      {
        if (*pin < 5)
        {
          *pout++ = *pin;
        }
      }
      etl::copy_n_if(std::begin(data1), 6, std::begin(data3), std::bind2nd(std::less<int>(), 5));

      bool is_same = std::equal(std::begin(data2), std::end(data2), std::begin(data3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(copy_if_4_parameter)
    {
      int data1[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };

      int out1[4];
      int out2[2];
      int out3[10];

      int check1[] = { 1, 2, 3, 4 };
      int check2[] = { 1, 2 };
      int check3[] = { 1, 2, 3, 4, 0, 0, 0, 0, 0, 0 };

      int* result;

      // Exact size.
      std::fill(std::begin(out1), std::end(out1), 0);
      result = etl::copy_if(std::begin(data1), std::end(data1), std::begin(out1), std::end(out1), std::bind2nd(std::less<int>(), 5));
      CHECK_EQUAL(std::end(out1), result);
      bool is_same = std::equal(std::begin(out1), std::end(out1), std::begin(check1));
      CHECK(is_same);

      // Destination smaller.
      std::fill(std::begin(out2), std::end(out2), 0);
      result = etl::copy_if(std::begin(data1), std::end(data1), std::begin(out2), std::end(out2), std::bind2nd(std::less<int>(), 5));
      CHECK_EQUAL(std::end(out2), result);
      is_same = std::equal(std::begin(out2), std::end(out2), std::begin(check2));
      CHECK(is_same);

      // Destination larger.
      std::fill(std::begin(out3), std::end(out3), 0);
      result = etl::copy_if(std::begin(data1), std::end(data1), std::begin(out3), std::end(out3), std::bind2nd(std::less<int>(), 5));
      CHECK_EQUAL(std::begin(out3) + 4, result);
      is_same = std::equal(std::begin(out3), std::end(out3), std::begin(check3));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(any_of)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

      bool expected = std::any_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      bool result = etl::any_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      CHECK_EQUAL(expected, result);

      expected = std::any_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 0));
      result = etl::any_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 0));
      CHECK_EQUAL(expected, result);
    }

    //=========================================================================
    TEST(all_of)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

      bool expected = std::all_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 0));
      bool result = etl::all_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 0));
      CHECK_EQUAL(expected, result);

      expected = std::all_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      result = etl::all_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      CHECK_EQUAL(expected, result);
    }

    //=========================================================================
    TEST(none_of)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

      bool expected = std::none_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 8));
      bool result = etl::none_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 8));
      CHECK_EQUAL(expected, result);

      expected = std::none_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      result = etl::none_of(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      CHECK_EQUAL(expected, result);
    }

    struct Compare : public std::binary_function < int, int, bool >
    {
      bool operator()(int a, int b) const
      {
        return a == b;
      }
    };

    //=========================================================================
    TEST(is_permutation)
    {
      int data1[]           = { 1, 2, 3, 4, 5, 6, 7, 8 };
      int permutation[]     = { 1, 3, 2, 4, 7, 6, 5, 8 };
      int not_permutation[] = { 1, 2, 3, 4, 5, 6, 7, 7 };

      bool is_permutation   = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(permutation));
      CHECK(is_permutation);

      is_permutation   = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(not_permutation));
      CHECK(!is_permutation);

      is_permutation = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(permutation), std::equal_to<int>());
      CHECK(is_permutation);

      is_permutation = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(not_permutation), std::equal_to<int>());
      CHECK(!is_permutation);

      is_permutation   = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(permutation), std::end(permutation));
      CHECK(is_permutation);

      is_permutation   = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(not_permutation), std::end(not_permutation));
      CHECK(!is_permutation);

      is_permutation = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(permutation), std::end(permutation), std::equal_to<int>());
      CHECK(is_permutation);

      is_permutation = etl::is_permutation(std::begin(data1), std::end(data1), std::begin(not_permutation), std::end(not_permutation), std::equal_to<int>());
      CHECK(!is_permutation);
    }

    //=========================================================================
    TEST(is_partitioned)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8 };

      bool expected = std::is_partitioned(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      bool result = etl::is_partitioned(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      CHECK_EQUAL(expected, result);

      std::partition(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));

      expected = std::is_partitioned(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      result = etl::is_partitioned(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      CHECK_EQUAL(expected, result);
    }

    //=========================================================================
    TEST(partition_point)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8 };

      std::partition(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));

      int* partition1 = std::partition_point(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      int* partition2 = etl::partition_point(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 4));
      CHECK_EQUAL(std::distance(std::begin(data1), partition1), std::distance(std::begin(data1), partition2));

      std::partition(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 8));

      partition1 = std::partition_point(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 0));
      partition2 = etl::partition_point(std::begin(data1), std::end(data1), std::bind2nd(std::greater<int>(), 0));
      CHECK_EQUAL(std::distance(std::begin(data1), partition1), std::distance(std::begin(data1), partition2));
    }

    //=========================================================================
    TEST(partition_copy)
    {
      int data1[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
      int data2[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
      int data3[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
      int data4[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
      int data5[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

      std::partition_copy(std::begin(data1), std::end(data1), std::begin(data2),  std::begin(data3), std::bind2nd(std::greater<int>(), 4));
      etl::partition_copy(std::begin(data1), std::end(data1), std::begin(data4),  std::begin(data5), std::bind2nd(std::greater<int>(), 4));

      bool are_equal;

      are_equal = std::equal(std::begin(data2), std::end(data2), std::begin(data4));
      CHECK(are_equal);

      are_equal = std::equal(std::begin(data3), std::end(data3), std::begin(data5));
      CHECK(are_equal);
    }

    //=========================================================================
    TEST(find_if_not)
    {
      int data1[] = { 1, 2, 3, 5, 6, 7, 8 };

      // Find the element not less than 4.
      int* p = std::find_if_not(std::begin(data1), std::end(data1), std::bind2nd(std::less<int>(), 4));
      CHECK_EQUAL(5, *p);
    }

    //=========================================================================
    TEST(for_each_if)
    {
      int data1[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };

      struct Sum
      {
        Sum() : sum(0) { }

        Sum& operator()(int i)
        {
          sum += i;

          return *this;
        }

        int sum;
      } accumulator;

      // For each if everything less than 5.
      accumulator = etl::for_each_if(std::begin(data1),
                                     std::end(data1),
                                     accumulator,
                                     std::bind2nd(std::less<int>(), 5));

      CHECK_EQUAL(10, accumulator.sum);
    }

    //=========================================================================
    TEST(for_each_n)
    {
      int data1[] = { 1,  8, 2, 7,  3, 6, 4, 5, 10, 9 };
      int data2[] = { 2, 16, 4, 14, 6, 6, 4, 5, 10, 9 };

      struct Multiply
      {
        void operator()(int& i)
        {
          i *= 2;
        }
      } multiplier;

      etl::for_each_n(std::begin(data1), 5, multiplier);

      bool are_equal = std::equal(std::begin(data1), std::end(data1), std::begin(data2));
      CHECK(are_equal);
    }

    //=========================================================================
    TEST(for_each_n_if)
    {
      int data1[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int data2[] = { 2, 8, 4, 7, 6, 6, 4, 5, 10, 9 };

      struct Multiply
      {
        void operator()(int& i)
        {
          i *= 2;
        }
      } multiplier;

      etl::for_each_n_if(std::begin(data1), 5, multiplier, std::bind2nd(std::less<int>(), 5));

      bool are_equal = std::equal(std::begin(data1), std::end(data1), std::begin(data2));
      CHECK(are_equal);
    }

    //=========================================================================
    TEST(transform_4_parameter)
    {
      int input[]   = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int output[]  = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int compare[] = { 2, 16, 4, 14, 6, 0, 0, 0, 0, 0 };

      // Double everything and copy to output.
      etl::transform(std::begin(input),
                     std::end(input),
                     std::begin(output),
                     std::begin(output) + (etl::size(output) / 2),
                     std::bind2nd(std::multiplies<int>(), 2));

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);

      std::fill(std::begin(output), std::end(output), 0);

      etl::transform(std::begin(input),
                     std::begin(input) + (etl::size(input) / 2),
                     std::begin(output),
                     std::end(output),
                     std::bind2nd(std::multiplies<int>(), 2));

      is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(transform_n_random_iterator)
    {
      int input[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int output[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int compare[] = { 2, 16, 4, 14, 6, 12, 8, 0, 0, 0 };

      etl::transform_n(std::begin(input),
                       7,
                       std::begin(output),
                       std::bind2nd(std::multiplies<int>(), 2));

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(transform_n_non_random_iterator)
    {
      std::list<int> input = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int output[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int compare[] = { 2, 16, 4, 14, 6, 12, 8, 0, 0, 0 };

      etl::transform_n(std::begin(input),
                       7,
                       std::begin(output),
                       std::bind2nd(std::multiplies<int>(), 2));

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(transform_if)
    {
      int input[]   = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int output[]  = { 0, 0, 0, 0, 0, 0, 0, 0,  0, 0 };
      int compare[] = { 2, 4, 6, 8, 0, 0, 0, 0,  0, 0 };

      // Double everything less than 5 and copy to output.
      etl::transform_if(std::begin(input),
                        std::end(input),
                        std::begin(output),
                        std::bind2nd(std::multiplies<int>(), 2),
                        std::bind2nd(std::less<int>(), 5));

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(transform_if_2_input_ranges)
    {
      int input1[] = { 1, 8, 2, 7, 3,  6, 4, 5, 10, 9 };
      int input2[] = { 8, 7, 6, 5, 4, 10, 9, 3,  2, 1 };
      int output[]  = { 0, 0, 0, 0, 0, 0, 0, 0,  0, 0 };
      int compare[] = { 8, 12, 12, 60, 36, 0, 0, 0,  0, 0 };

      // Multiply together everything where input1 is less than input2 and copy to output.
      etl::transform_if(std::begin(input1),
                        std::end(input1),
                        std::begin(input2),
                        std::begin(output),
                        std::multiplies<int>(),
                        std::less<int>());

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(transform_n_if)
    {
      int input[] = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int output[] = { 0, 0, 0, 0, 0, 0, 0, 0,  0, 0 };
      int compare[] = { 2, 4, 6, 0, 0, 0, 0, 0,  0, 0 };

      // Double everything less than 5 and copy to output.
      etl::transform_n_if(std::begin(input),
                          5,
                          std::begin(output),
                          std::bind2nd(std::multiplies<int>(), 2),
                          std::bind2nd(std::less<int>(), 5));

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(transform_n_if_2_input_ranges)
    {
      int input1[] = { 1, 8, 2, 7, 3,  6, 4, 5, 10, 9 };
      int input2[] = { 8, 7, 6, 5, 4, 10, 9, 3,  2, 1 };
      int output[] = { 0, 0, 0, 0, 0, 0, 0, 0,  0, 0 };
      int compare[] = { 8, 12, 12, 0, 0, 0, 0, 0,  0, 0 };

      // Multiply together everything where input1 is less than input2 and copy to output.
      etl::transform_n_if(std::begin(input1),
                          std::begin(input2),
                          5,
                          std::begin(output),
                          std::multiplies<int>(),
                          std::less<int>());

      bool is_same = std::equal(std::begin(output), std::end(output), std::begin(compare));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(partition_transform)
    {
      int input[]         = { 1, 8, 2, 7, 3, 6, 4, 5, 10, 9 };
      int output_true[]   = { 0, 0, 0, 0, 0, 0, 0, 0,  0, 0 };
      int output_false[]  = { 0, 0, 0, 0, 0, 0, 0, 0,  0, 0 };
      int compare_true[]  = { 2, 4, 6, 8, 0, 0, 0, 0,  0, 0 };
      int compare_false[] = { -16, -14, -12, -10, -20, -18, 0, 0, 0, 0 };

      // Multiply everything less than 5 by 2 and copy to output_true.
      // Multiply everything not less than 5 by -2 and copy to output_false.
      etl::partition_transform(std::begin(input),
                               std::end(input),
                               std::begin(output_true),
                               std::begin(output_false),
                               std::bind2nd(std::multiplies<int>(), 2),
                               std::bind2nd(std::multiplies<int>(), -2),
                               std::bind2nd(std::less<int>(), 5));

      bool is_same = std::equal(std::begin(output_true), std::end(output_true), std::begin(compare_true));
      CHECK(is_same);

      is_same = std::equal(std::begin(output_false), std::end(output_false), std::begin(compare_false));
      CHECK(is_same);
    }

    //=========================================================================
    TEST(partition_transform_2_input_ranges)
    {
      int input1[] = { 1, 8, 2, 7, 3,  6, 4, 5, 10, 9 };
      int input2[] = { 8, 7, 6, 5, 4, 10, 9, 3,  2, 1 };
      int output_true[]  = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int output_false[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      int compare_true[]  = { 8, 12, 12, 60, 36, 0, 0, 0, 0, 0 };
      int compare_false[] = { 15, 12, 8, 12, 10, 0, 0, 0, 0, 0 };

      // If input1 < input2 multiply else add.
      etl::partition_transform(std::begin(input1),
                               std::end(input1),
                               std::begin(input2),
                               std::begin(output_true),
                               std::begin(output_false),
                               std::multiplies<int>(),
                               std::plus<int>(),
                               std::less<int>());

      bool is_same = std::equal(std::begin(output_true), std::end(output_true), std::begin(compare_true));
      CHECK(is_same);

      is_same = std::equal(std::begin(output_false), std::end(output_false), std::begin(compare_false));
      CHECK(is_same);
    }
  };
}