etl/test/test_not_null_pointer_constexpr.cpp

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

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

Copyright(c) 2025 John Wellbelove

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#include "etl/not_null.h"
#include "unit_test_framework.h"

#if ETL_USING_CPP14
namespace
{
  struct S
  {
    int x;

    constexpr int get() const
    {
      return x;
    }
  };

  //*************************************************************************
  constexpr etl::not_null<const int*> CreateNotNullAssignFromPointer(const int* p1, const int* p2)
  {
    // Create a not_null pointer from a pointer.
    etl::not_null<const int*> nn(p1);

    // Assign a different pointer to the not_null.
    nn = p2;

    return nn;
  }

  //*************************************************************************
  constexpr etl::not_null<const int*> CreateNotNullAssignFromNotNull(const int* p1, const int* p2)
  {
    // Create a not_null pointer from a pointer.
    etl::not_null<const int*> nn1(p1);
    etl::not_null<const int*> nn2(p2);

    nn1 = nn2;

    return nn1;
  }

  SUITE(test_not_null_pointer)
  {
    //*************************************************************************
    TEST(test_construct_from_non_null_pointer)
    {
      static constexpr const int                 value = 123;
      static constexpr etl::not_null<const int*> nn(&value);
      static constexpr const int*                p = nn.get();
      static constexpr const int                 v = *nn;
      CHECK_EQUAL(&value, p);
      CHECK_EQUAL(123, v);
    }

    //*************************************************************************
    TEST(test_copy_construct)
    {
      static constexpr const int                 value = 123;
      static constexpr etl::not_null<const int*> nn1(&value);
      static constexpr etl::not_null<const int*> nn2(nn1); // Copy constructor
      static constexpr const int*                p = nn2.get();
      static constexpr const int                 v = *nn2;
      CHECK_EQUAL(&value, p);
      CHECK_EQUAL(123, v);
    }

    //*************************************************************************
    TEST(test_assign_from_pointer)
    {
      static constexpr const int                 value1 = 123;
      static constexpr const int                 value2 = 456;
      static constexpr etl::not_null<const int*> nn(CreateNotNullAssignFromPointer(&value1, &value2));

      CHECK_EQUAL(&value2, nn.get());
      CHECK_EQUAL(456, *nn);
    }

    //*************************************************************************
    TEST(test_assign_from_not_null)
    {
      static constexpr const int                 value1 = 123;
      static constexpr const int                 value2 = 456;
      static constexpr etl::not_null<const int*> nn(CreateNotNullAssignFromNotNull(&value1, &value2));

      CHECK_EQUAL(&value2, nn.get());
      CHECK_EQUAL(456, *nn);
    }

    //*************************************************************************
    TEST(test_implicit_conversion)
    {
      static constexpr const S                 s{123};
      static constexpr etl::not_null<const S*> nn(&s);

      static constexpr const S* raw = nn;
      CHECK_EQUAL(&s, raw);
    }

    //*************************************************************************
    TEST(test_arrow_operator)
    {
      static constexpr const S                 s{123};
      static constexpr etl::not_null<const S*> nn(&s);

      static constexpr int x1 = nn->x;
      static constexpr int x2 = nn->get();

      CHECK_EQUAL(s.x, x1);
      CHECK_EQUAL(s.get(), x2);
    }

    //*************************************************************************
    TEST(test_dereference_operator)
    {
      static constexpr const S                 s{123};
      static constexpr etl::not_null<const S*> nn(&s);

      static constexpr int x1 = (*nn).x;
      static constexpr int x2 = (*nn).get();

      CHECK_EQUAL(s.x, x1);
      CHECK_EQUAL(s.get(), x2);
    }
  }
} // namespace

#endif