etl/test/test_hash.cpp

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

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

Copyright(c) 2014 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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The above copyright notice and this permission notice shall be included in all
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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 <iterator>
#include <stdint.h>
#include <string>
#include <type_traits>
#include <vector>

#include "etl/endianness.h"
#include "etl/hash.h"

// for testing user-defined hash specializations
namespace
{
  class CustomType
  {
  };
} // namespace
namespace etl
{
  template <>
  struct hash<CustomType>
  {
    size_t operator()(CustomType)
    {
      return 0;
    }
  };
} // namespace etl

namespace
{
  SUITE(test_hash)
  {
    //*************************************************************************
    TEST(test_hash_bool)
    {
      size_t hash = etl::hash<bool>()(false);
      CHECK_EQUAL(0U, hash);

      hash = etl::hash<bool>()(true);
      CHECK_EQUAL(1U, hash);
    }

    //*************************************************************************
    TEST(test_hash_char)
    {
      size_t hash = etl::hash<char>()(0x5A);

      CHECK_EQUAL(0x5AU, hash);
    }

    //*************************************************************************
    TEST(test_hash_signed_char)
    {
      size_t hash = etl::hash<signed char>()(0x5A);

      CHECK_EQUAL(0x5AU, hash);
    }

    //*************************************************************************
    TEST(test_hash_unsigned_char)
    {
      size_t hash = etl::hash<unsigned char>()(0x5AU);

      CHECK_EQUAL(0x5AU, hash);
    }

    //*************************************************************************
    TEST(test_hash_short)
    {
      size_t hash = etl::hash<short>()(0x5AA5);

      CHECK_EQUAL(0x5AA5U, hash);
    }

    //*************************************************************************
    TEST(test_hash_unsigned_short)
    {
      size_t hash = etl::hash<unsigned short>()(0x5AA5U);

      CHECK_EQUAL(0x5AA5U, hash);
    }

    //*************************************************************************
    TEST(test_hash_int)
    {
      size_t hash = etl::hash<int>()(0x5AA555AA);

      CHECK_EQUAL(0x5AA555AAUL, hash);
    }

    //*************************************************************************
    TEST(test_hash_unsigned_int)
    {
      size_t hash = etl::hash<unsigned int>()(0x5AA555AAU);

      CHECK_EQUAL(0x5AA555AAUL, hash);
    }

    //*************************************************************************
    TEST(test_hash_long)
    {
      size_t hash = etl::hash<long>()(0x5AA555AAL);

      CHECK_EQUAL(0x5AA555AAUL, hash);
    }

    //*************************************************************************
    TEST(test_hash_unsigned_long)
    {
      size_t hash = etl::hash<unsigned long>()(0x5AA555AAUL);

      CHECK_EQUAL(0x5AA555AAUL, hash);
    }

    //*************************************************************************
    TEST(test_hash_long_long)
    {
      size_t hash = etl::hash<long long>()(0x5AA555AA3CC333CCLL);

      if (ETL_PLATFORM_32BIT)
      {
        if (etl::endianness::value() == etl::endian::little)
        {
          CHECK_EQUAL(0xEC6A8D69UL, hash);
        }
        else
        {
          CHECK_EQUAL(0x5F69FD19UL, hash);
        }
      }

      if (ETL_PLATFORM_64BIT)
      {
        CHECK_EQUAL(0x5AA555AA3CC333CCULL, hash);
      }
    }

    //*************************************************************************
    TEST(test_hash_unsigned_long_long)
    {
      size_t hash = etl::hash<unsigned long long>()(0x5AA555AA3CC333CCULL);

      if (ETL_PLATFORM_32BIT)
      {
        if (etl::endianness::value() == etl::endian::little)
        {
          CHECK_EQUAL(0xEC6A8D69UL, hash);
        }
        else
        {
          CHECK_EQUAL(0x5F69FD19UL, hash);
        }
      }

      if (ETL_PLATFORM_64BIT)
      {
        CHECK_EQUAL(0x5AA555AA3CC333CCULL, hash);
      }
    }

    //*************************************************************************
    TEST(test_hash_float)
    {
      size_t hash = etl::hash<float>()(1.2345f);

      if (ETL_PLATFORM_32BIT)
      {
        CHECK_EQUAL(0X3F9E0419U, hash);
      }

      if (ETL_PLATFORM_64BIT)
      {
        if (etl::endianness::value() == etl::endian::little)
        {
          CHECK_EQUAL(9821047038287739023U, hash);
        }
        else
        {
          CHECK_EQUAL(15239628249615675935U, hash);
        }
      }
    }

    //*************************************************************************
    TEST(test_hash_double)
    {
      size_t hash = etl::hash<double>()(1.2345);

      if (ETL_PLATFORM_32BIT)
      {
        if (etl::endianness::value() == etl::endian::little)
        {
          CHECK_EQUAL(0x86FBF224UL, hash);
        }
        else
        {
          CHECK_EQUAL(0xD1F372DEUL, hash);
        }
      }

      if (ETL_PLATFORM_64BIT)
      {
        CHECK_EQUAL(0x3FF3C083126E978DULL, hash);
      }
    }

    TEST(test_hash_floating_point_negative_zero)
    {
      if (sizeof(float) == sizeof(size_t))
      {
        etl::hash<float> hasher{};
        size_t           hash1 = hasher(0.0);
        size_t           hash2 = hasher(-0.0);
        CHECK_EQUAL(hash1, hash2);
      }

      if (sizeof(double) == sizeof(size_t))
      {
        etl::hash<double> hasher{};
        size_t            hash1 = hasher(0.0);
        size_t            hash2 = hasher(-0.0);
        CHECK_EQUAL(hash1, hash2);
      }

      if (sizeof(long double) == sizeof(size_t))
      {
        etl::hash<long double> hasher{};
        size_t                 hash1 = hasher(0.0);
        size_t                 hash2 = hasher(-0.0);
        CHECK_EQUAL(hash1, hash2);
      }
    }

    //*************************************************************************
    TEST(test_hash_pointer)
    {
      int    i{};
      size_t hash = etl::hash<int*>()(&i);

      CHECK_EQUAL(size_t(&i), hash);
    }

    //*************************************************************************
    TEST(test_hash_const_pointer)
    {
      int    i{};
      size_t hash = etl::hash<const int*>()(&i);

      CHECK_EQUAL(size_t(&i), hash);
    }

    //*************************************************************************
    TEST(test_hash_const_pointer_const)
    {
      int              i{};
      const int* const pi = &i;

      size_t hash = etl::hash<const int*>()(pi);

      CHECK_EQUAL(size_t(&i), hash);
    }

    //*************************************************************************
    TEST(test_hash_enums)
    {
      enum class MyEnumClass : char
      {
        OneE = 0x1E
      };

      enum MyEnum : char
      {
        MyEnum_TwoF = 0x2F
      };

      size_t hash = etl::hash<MyEnumClass>()(MyEnumClass::OneE);
      CHECK_EQUAL(static_cast<size_t>(MyEnumClass::OneE), hash);

      hash = etl::hash<MyEnum>()(MyEnum_TwoF);
      CHECK_EQUAL(0x2F, hash);
    }

    //*************************************************************************
    TEST(test_hash_big_enums)
    {
      constexpr unsigned long long big_number = 0x5AA555AA3CC333CCULL;
      enum class MyBigEnumClass : unsigned long long
      {
        Big = big_number
      };

      size_t hash         = etl::hash<MyBigEnumClass>()(MyBigEnumClass::Big);
      size_t expectedHash = etl::hash<unsigned long long>()(big_number);
      CHECK_EQUAL(expectedHash, hash);
    }

    //*************************************************************************
    TEST(test_hash_poisoned)
    {
      // Unspecialized hash<> should be disabled (unusable) - see
      // https://en.cppreference.com/w/cpp/utility/hash
      class A
      {
      };
      typedef etl::hash<A> general_hasher;

      CHECK_FALSE(std::is_default_constructible<general_hasher>::value);
      CHECK_FALSE(std::is_copy_constructible<general_hasher>::value);
      CHECK_FALSE(std::is_move_constructible<general_hasher>::value);
      CHECK_FALSE(std::is_copy_assignable<general_hasher>::value);
      CHECK_FALSE(std::is_move_assignable<general_hasher>::value);
    }

    //*************************************************************************
    TEST(test_hash_custom)
    {
      typedef etl::hash<CustomType> custom_hasher;

      CHECK_TRUE(std::is_default_constructible<custom_hasher>::value);
      CHECK_TRUE(std::is_copy_constructible<custom_hasher>::value);
      CHECK_TRUE(std::is_move_constructible<custom_hasher>::value);
      CHECK_TRUE(std::is_copy_assignable<custom_hasher>::value);
      CHECK_TRUE(std::is_move_assignable<custom_hasher>::value);
    }
  }
} // namespace