etl/test/test_inplace_function.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 "unit_test_framework.h"

#include "etl/inplace_function.h"
#include "etl/vector.h"

#include <vector>
#include <functional>
#include <algorithm>
#include <type_traits>
#include <stdexcept>

// Enable exactly one of these at a time to see the corresponding static_assert fire.
//#define ETL_NEGATIVE_TEST_INPLACE_FUNCTION_BAD_RETURN
//#define ETL_NEGATIVE_TEST_INPLACE_FUNCTION_RVALUE_PARAM_MISMATCH_NONCONST
//#define ETL_NEGATIVE_TEST_INPLACE_FUNCTION_RVALUE_PARAM_MISMATCH_CONST

namespace
{
  //*****************************************************************************
  enum class FunctionCalled : int
  {
    Not_Called,
    Free_Void_Called,
    Free_Int_Called,
    Free_Reference_Called,
    Free_Moveableonly_Called,
    Normal_Called,
    Normal_Returning_Void_Called,
    Alternative_Called,
    Member_Void_Called,
    Member_Void_Const_Called,
    Member_Int_Called,
    Member_Int_Const_Called,
    Member_Reference_Called,
    Member_Reference_Const_Called,
    Member_Moveableonly_Called,
    Member_Static_Called,
    Operator_Called,
    Operator_Const_Called,
    Lambda_Called
  };

  FunctionCalled function_called = FunctionCalled::Not_Called;

  //*****************************************************************************
  const int VALUE1 = 1;
  const int VALUE2 = 2;
  bool parameter_correct = false;

  //*****************************************************************************
  // Object data structure.
  //*****************************************************************************
  struct Data
  {
    int ipf;
  };

  //*****************************************************************************
  // Object moveable only data structure.
  //*****************************************************************************
  struct MoveableOnlyData
  {
    MoveableOnlyData() = default;
    ~MoveableOnlyData() = default;
    MoveableOnlyData(const MoveableOnlyData&) = delete;
    MoveableOnlyData& operator=(const MoveableOnlyData&) = delete;
    MoveableOnlyData(MoveableOnlyData&&) = default;
    MoveableOnlyData& operator=(MoveableOnlyData&&) = default;
    int ipf;
  };

  //*****************************************************************************
  // The free function taking no parameters.
  //*****************************************************************************
  static void free_void()
  {
    function_called = FunctionCalled::Free_Void_Called;
  }

  //*****************************************************************************
  // The free function taking an int parameter.
  //*****************************************************************************
  void free_int(int i, int j)
  {
    function_called = FunctionCalled::Free_Int_Called;
    parameter_correct = (i == VALUE1) && (j == VALUE2);
  }

  //*****************************************************************************
  // The free function taking a Data reference parameter.
  //*****************************************************************************
  void free_reference(const Data& data, int j)
  {
    function_called = FunctionCalled::Free_Reference_Called;
    parameter_correct = (data.ipf == VALUE1) && (j == VALUE2);
  }

  //*****************************************************************************
  // The free function taking a moveable only parameter.
  //*****************************************************************************
  void free_moveableonly(MoveableOnlyData&& data)
  {
    function_called = FunctionCalled::Free_Moveableonly_Called;
    parameter_correct = (data.ipf == VALUE1);
  }

  //*****************************************************************************
  // The normal function.
  //*****************************************************************************
  int normal(int i, int j)
  {
    function_called = FunctionCalled::Normal_Called;
    parameter_correct = (i == VALUE1) && (j == VALUE2);

    return i + j;
  }

  //*****************************************************************************
  // The normal function returning void.
  //*****************************************************************************
  void normal_returning_void(int i, int j)
  {
    function_called = FunctionCalled::Normal_Returning_Void_Called;
    parameter_correct = (i == VALUE1) && (j == VALUE2);
  }

  //*****************************************************************************
  // The alternative function.
  //*****************************************************************************
  int alternative(int i, int j)
  {
    function_called = FunctionCalled::Alternative_Called;
    parameter_correct = (i == VALUE1) && (j == VALUE2);

    return i + j + 1;
  }

  //*****************************************************************************
  // The throwing function.
  //*****************************************************************************
  void throwing_void()
  {
    throw std::runtime_error("throwing function");
  }

  int throwing_normal(int, int)
  {
    throw std::runtime_error("throwing function with two parameters");
  }

  //*******************************************
  // Functor with non-const operator()
  struct Functor
  {
    void operator()()
    {
      function_called = FunctionCalled::Operator_Called;
    }
  };

  //*******************************************
  // Functor with const operator()
  struct FunctorConst
  {
    void operator()() const
    {
      function_called = FunctionCalled::Operator_Const_Called;
    }
  };

  //*******************************************
  int times_2(int a) 
  {
    return a * 2;
  }

  //*******************************************
  // Free int return.
  int free_int_return(int i, int j)
  {
    return i + j;
  }

#if ETL_USING_CPP17
  static auto global_lambda = [](int i, int j)
    {
      function_called = FunctionCalled::Lambda_Called;
      parameter_correct = (i == VALUE1) && (j == VALUE2);
    };
#endif

  //*******************************************
  // Functor with that is destructible and movable
  //*******************************************
  struct DestructibleMovableObject
  {
    DestructibleMovableObject()
      : call_count(0)
    {
      destructor_called        = false;
      copy_constructor_called  = false;
      move_constructor_called  = false;
      function_operator_called = false;
    }

    ~DestructibleMovableObject()
    {
      destructor_called = true;
    }

    DestructibleMovableObject(const DestructibleMovableObject& other)
      : call_count(other.call_count)
    {
      copy_constructor_called = true;
    }

    DestructibleMovableObject(DestructibleMovableObject&& other)
      : call_count(other.call_count)
    {
      move_constructor_called = true;
    }

    void operator()(int, int)
    {
      function_operator_called = true;
      ++call_count;
    }

    static bool destructor_called;
    static bool copy_constructor_called;
    static bool move_constructor_called;
    static bool function_operator_called;

    int call_count;
  };

  bool DestructibleMovableObject::destructor_called        = false;
  bool DestructibleMovableObject::copy_constructor_called  = false;
  bool DestructibleMovableObject::move_constructor_called  = false;
  bool DestructibleMovableObject::function_operator_called = false;

  //*******************************************
  // Sized functor
  template <size_t Size>
  struct FunctorSized
  {
    FunctorSized()
      : data()
    {
    }

    int operator()()
    {
      function_called = FunctionCalled::Operator_Called;

      return Size;
    }

    int size() const
    {
      return Size;
    }

    char data[Size];
  };
}

//*****************************************************************************
// The test class with member functions.
//*****************************************************************************
class Object
{
public:

  //*******************************************
  constexpr Object()
    : call_count(0)
  {
  }

  //*******************************************
  // void
  void member_void()
  {
    function_called = FunctionCalled::Member_Void_Called;
  }

  void member_void_const() const
  {
    function_called = FunctionCalled::Member_Void_Const_Called;
  }

  //*******************************************
  // int
  int member_int(int i, int j)
  {
    function_called = FunctionCalled::Member_Int_Called;
    parameter_correct = (i == VALUE1) && (j == VALUE2);

    ++call_count;

    return i + j + 1; 
  }

  int member_int_const(int i, int j) const
  {
    function_called = FunctionCalled::Member_Int_Const_Called;
    parameter_correct = (i == VALUE1) && (j == VALUE2);

    ++call_count;

    return i + j + 1;
  }

  //*******************************************
  // reference
  void member_reference(const Data& data, int j)
  {
    function_called = FunctionCalled::Member_Reference_Called;
    parameter_correct = (data.ipf == VALUE1) && (j == VALUE2);
  }

  void member_reference_const(const Data& data, int j) const
  {
    function_called = FunctionCalled::Member_Reference_Const_Called;
    parameter_correct = (data.ipf == VALUE1) && (j == VALUE2);

    ++call_count;
  }

  //*******************************************
  // moveable only data
  void member_moveableonly(MoveableOnlyData&& data)
  {
    function_called = FunctionCalled::Member_Moveableonly_Called;
    parameter_correct = (data.ipf == VALUE1);

    ++call_count;
  }

  //*******************************************
  // static
  static void member_static(const Data& data, int j)
  {
    function_called = FunctionCalled::Member_Static_Called;
    parameter_correct = (data.ipf == VALUE1) && (j == VALUE2);
  }

  //*******************************************
  // operator()
  void operator()()
  {
    function_called = FunctionCalled::Operator_Called;

    ++call_count;
  }

  //*******************************************
  // operator() const
  void operator()() const
  {
    function_called = FunctionCalled::Operator_Const_Called;

    ++call_count;
  }

  mutable int call_count;
};

Object object_static;
constexpr const Object const_object_static;

Functor functor_static;
const FunctorConst const_functor_static;

namespace
{
  //*****************************************************************************
  // Initialises the test results.
  //*****************************************************************************
  struct SetupFixture
  {
    SetupFixture()
    {
      function_called   = FunctionCalled::Not_Called;
      parameter_correct = false;
    }
  };

  SUITE(test_inplace_function)
  {
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_inplace_function_types)
    {
      using InplaceFunction = etl::inplace_function<int(float, long)>;

      // Check the return type.
      CHECK_TRUE((std::is_same<InplaceFunction::return_type, int>::value));

      // Check the argument types.
      CHECK_TRUE((std::is_same<InplaceFunction::argument_types, etl::type_list<float, long>>::value));
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_inplace_function_size_and_alignment)
    {
      using InplaceFunction84  = etl::inplace_function<int(float, long),  8, 4>;
      using InplaceFunction168 = etl::inplace_function<int(float, long), 16, 8>;

      // Check the sizes.
      CHECK_EQUAL(8,  InplaceFunction84::size());
      CHECK_EQUAL(16, InplaceFunction168::size());

      // Check the alignments.
      CHECK_EQUAL(4, InplaceFunction84::alignment());
      CHECK_EQUAL(8, InplaceFunction168::alignment());
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_is_valid_false)
    {
      etl::inplace_function<void(void)> ipf;

      CHECK(!ipf.is_valid());
      CHECK(!ipf);

      CHECK_THROW(ipf(), etl::inplace_function_uninitialized);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_is_valid_true)
    {
      auto lambda = [] {};

      etl::inplace_function<void(void)> ipf(lambda);

      CHECK(ipf.is_valid());
      CHECK(ipf);
      CHECK_NO_THROW(ipf());
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_is_valid_after_clear)
    {
      auto lambda = [] {};

      etl::inplace_function<void(void)> ipf(lambda);

      CHECK_TRUE(ipf.is_valid());
      ipf.clear();
      CHECK_FALSE(ipf.is_valid());
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_void_run_time)
    {
      etl::inplace_function<void(void)> ipf(free_void);

      ipf();

      CHECK(function_called == FunctionCalled::Free_Void_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_void_compile_time)
    {
      auto ipf = etl::inplace_function<void(void)>::create<free_void>();

      ipf();

      CHECK(function_called == FunctionCalled::Free_Void_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_void_run_time)
    {
      auto ipf = etl::make_inplace_function(free_void);

      ipf();

      CHECK(function_called == FunctionCalled::Free_Void_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_construct_from_nullptr)
    {
      etl::inplace_function<void(void)> ipf(nullptr);

      CHECK_FALSE(ipf.is_valid());
      CHECK_FALSE(ipf);
      CHECK_THROW(ipf(), etl::inplace_function_uninitialized);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_void_compile_time)
    {
      auto ipf = etl::make_inplace_function<&free_void>();

      ipf();

      CHECK(function_called == FunctionCalled::Free_Void_Called);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_throwing)
    {
      {
        auto ipf = etl::inplace_function<void(void)>::create<throwing_void>();

        CHECK_THROW(ipf(),         std::runtime_error);
        CHECK_THROW(ipf.call_if(), std::runtime_error);
      }

      {
        auto ipf = etl::inplace_function<int(int, int)>::create<throwing_normal>();

        CHECK_THROW({ipf.call_or(alternative, VALUE1, VALUE2);}, std::runtime_error);
        CHECK_THROW({ipf.call_or<alternative>(VALUE1, VALUE2);}, std::runtime_error);
      }
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_int_run_time)
    {
      etl::inplace_function<void(int, int)> ipf(free_int);

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Int_Called);
      CHECK(parameter_correct);
    }
    
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_int_compile_time)
    {
      auto ipf = etl::inplace_function<void(int, int)>::create<free_int>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_int_run_time)
    {
      auto ipf = etl::make_inplace_function(free_int);

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Int_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_int_compile_time)
    {
      auto ipf = etl::make_inplace_function<&free_int>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Int_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_reference_run_time)
    {
      etl::inplace_function<void(const Data&, int)> ipf(free_reference);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Reference_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_reference_compile_time)
    {
      auto ipf = etl::inplace_function<void(const Data&, int)>::create<free_reference>();

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Reference_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_reference_run_time)
    {
      auto ipf = etl::make_inplace_function(free_reference);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Reference_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_reference_compile_time)
    {
      auto ipf = etl::make_inplace_function<&free_reference>();

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Reference_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_moveableonly_run_time)
    {
      etl::inplace_function<void(MoveableOnlyData&&)> ipf(free_moveableonly);

      MoveableOnlyData data;
      data.ipf = VALUE1;

      ipf(std::move(data));

      CHECK(function_called == FunctionCalled::Free_Moveableonly_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_free_moveableonly_compile_time)
    {
      auto ipf = etl::inplace_function<void(MoveableOnlyData&&)>::create<free_moveableonly>();

      MoveableOnlyData data;
      data.ipf = VALUE1;

      ipf(std::move(data));

      CHECK(function_called == FunctionCalled::Free_Moveableonly_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_moveableonly_run_time)
    {
      auto ipf = etl::make_inplace_function(free_moveableonly);

      MoveableOnlyData data;
      data.ipf = VALUE1;

      ipf(std::move(data));

      CHECK(function_called == FunctionCalled::Free_Moveableonly_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_free_moveableonly_compile_time)
    {
      auto ipf = etl::make_inplace_function<&free_moveableonly>();

      MoveableOnlyData data;
      data.ipf = VALUE1;

      ipf(std::move(data));

      CHECK(function_called == FunctionCalled::Free_Moveableonly_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_lambda_int)
    {
      auto lambda = [](int i, int j) { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); };

      etl::inplace_function<void(int, int)> ipf(lambda);

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_lambda_int_run_time)
    {
      auto lambda = [](int i, int j) { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); };

      auto ipf = etl::make_inplace_function(lambda);

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_lambda_int_compile_time)
    {
      static auto lambda = [](int i, int j) { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); };

      auto ipf = etl::make_inplace_function<decltype(lambda), lambda>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_capturing_lambda_int)
    {
      int value = VALUE1;

      auto lambda = [value](int i, int j) -> int { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); return value + VALUE1 + VALUE2; };

      etl::inplace_function<int(int, int)> ipf(lambda);

      int result = ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
      CHECK_EQUAL(result, VALUE1 + VALUE1 + VALUE2);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_capturing_lambda_int_run_time)
    {
      int value = VALUE1;

      auto lambda = [value](int i, int j) -> int { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); return value + VALUE1 + VALUE2; };

      auto ipf = etl::make_inplace_function(lambda);

      int result = ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
      CHECK_EQUAL(result, VALUE1 + VALUE1 + VALUE2);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_capturing_lambda_int_compile_time)
    {
      int value = VALUE1;

      static auto lambda = [value](int i, int j) -> int { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); return value + VALUE1 + VALUE2; };

      auto ipf = etl::make_inplace_function<decltype(lambda), lambda>();

      int result = ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
      CHECK_EQUAL(result, VALUE1 + VALUE1 + VALUE2);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_operator_void)
    {
      Object object;

      etl::inplace_function<void(void)> ipf(object);

      ipf();

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_operator_void_const)
    {
      const Object object;

      etl::inplace_function<void(void)> ipf(object);

      ipf();

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Operator_Const_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_operator_void_const)
    {
      const FunctorConst object;

      auto ipf = etl::make_inplace_function(object);

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Const_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_operator_void_compile_time)
    {
      auto ipf = etl::inplace_function<void(void)>::create<Object, object_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_operator_void_compile_time_const)
    {
      auto ipf = etl::inplace_function<void(void)>::create<const Object, const_object_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Const_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_functor_operator_void_run_time)
    {
      auto ipf = etl::make_inplace_function(functor_static);

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
#if ETL_USING_CPP17
    TEST_FIXTURE(SetupFixture, test_make_inplace_functor_operator_void_compile_time)
    {
      auto ipf = etl::make_inplace_function<Functor, functor_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Called);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_operator_const_void_run_time)
    {
      auto ipf = etl::make_inplace_function(const_functor_static);

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Const_Called);
    }

    //*************************************************************************
#if ETL_USING_CPP17
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_operator_const_void_compile_time)
    {
      auto ipf = etl::make_inplace_function<const FunctorConst, const_functor_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Const_Called);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_assignment_member_operator_void)
    {
      Object object;

      etl::inplace_function<void(void)> ipf;

      ipf = object;

      ipf();

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_void)
    {
      auto ipf = etl::inplace_function<void(void)>::create<Object, &Object::member_void, object_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Member_Void_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_void_run_time)
    {
      static Object object;

      auto ipf = etl::make_inplace_function(&Object::member_void, object);

      ipf();

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Void_Called);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_void_compile_time)
    {
      auto ipf = etl::make_inplace_function<Object, &Object::member_void, object_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Member_Void_Called);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_void_const)
    {
      auto ipf = etl::inplace_function<void(void)>::create<Object, &Object::member_void_const, const_object_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Member_Void_Const_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_void_const_run_time)
    {
      static const Object object;

      auto ipf = etl::make_inplace_function(&Object::member_void_const, object);

      ipf();

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Void_Const_Called);
    }

    //*************************************************************************
#if ETL_USING_CPP17
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_void_const_compile_time)
    {
      auto ipf = etl::make_inplace_function<Object, &Object::member_void_const, const_object_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Member_Void_Const_Called);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_int)
    {
      auto ipf = etl::inplace_function<int(int, int)>::create<Object, &Object::member_int, object_static>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_int_run_time)
    {
      Object object;

      auto ipf = etl::make_inplace_function(&Object::member_int, object); // Pass it by value to the inplace function.

      ipf(VALUE1, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
#if ETL_USING_CPP17
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_int_compile_time)
    {
      auto ipf = etl::make_inplace_function<Object, &Object::member_int, object_static>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Int_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_int_const)
    {
      auto ipf = etl::inplace_function<int(int, int)>::create<Object, &Object::member_int_const, object_static>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Int_Const_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_int_const_run_time)
    {
      Object object;

      auto ipf = etl::make_inplace_function(&Object::member_int_const, object);

      ipf(VALUE1, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Int_Const_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
#if ETL_USING_CPP17
    TEST_FIXTURE(SetupFixture, test_make_inplace_function_member_int_const_compile_time)
    {
      auto ipf = etl::make_inplace_function<Object, &Object::member_int_const, object_static>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Int_Const_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_reference)
    {
      Object object;
      auto ipf = etl::inplace_function<void(const Data&, int)>(&Object::member_reference, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Reference_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_member_reference_run_time)
    {
      Object object;
      auto ipf = etl::make_inplace_function(&Object::member_reference, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Reference_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_member_reference_compile_time)
    {
      auto ipf = etl::make_inplace_function<Object, &Object::member_reference, object_static>();

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Reference_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_reference_const)
    {
      Object object;
      auto ipf = etl::inplace_function<void(const Data&, int)>(&Object::member_reference_const, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Reference_Const_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_member_reference_run_time_const)
    {
      Object object;
      auto ipf = etl::make_inplace_function(&Object::member_reference_const, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Reference_Const_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_member_reference_compile_time_const)
    {
      auto ipf = etl::make_inplace_function<Object, &Object::member_reference_const, object_static>();

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Reference_Const_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_moveableonly)
    {
      Object object;
      auto ipf = etl::inplace_function<void(MoveableOnlyData&&)>(&Object::member_moveableonly, object);

      MoveableOnlyData data;
      data.ipf = VALUE1;

      ipf(std::move(data));

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Moveableonly_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_member_static)
    {
      auto ipf = etl::inplace_function<void(const Data&, int)>(Object::member_static);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Static_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_member_static_run_time)
    {
      auto ipf = etl::make_inplace_function(Object::member_static);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Static_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_make_member_static_compile_time)
    {
      auto ipf = etl::make_inplace_function<Object::member_static>();

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Static_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_free_int_run_time)
    {
      // Start with a destructible object to check that it is properly destroyed
      DestructibleMovableObject object;
      etl::inplace_function<void(int, int)> ipf(object);

      ipf.set(free_int);

      CHECK_TRUE(DestructibleMovableObject::destructor_called);

      ipf(VALUE1, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Free_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_free_int_compile_time)
    {
      etl::inplace_function<void(int, int)> ipf;

      ipf.set<&free_int>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Free_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_lambda_int_run_time)
    {
      etl::inplace_function<void(int, int)> ipf;

      auto lambda = [](int i, int j) { function_called = FunctionCalled::Lambda_Called; parameter_correct = (i == VALUE1) && (j == VALUE2); };

      ipf.set(lambda);

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
    }

#if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_lambda_int_compile_time)
    {
      etl::inplace_function<void(int, int)> ipf;

      ipf.set<global_lambda>();

      ipf(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Lambda_Called);
      CHECK(parameter_correct);
    }
#endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_functor_run_time)
    {
      etl::inplace_function<void(void)> ipf;

      Functor functor;

      ipf.set(functor);

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_functor_compile_time)
    {
      etl::inplace_function<void(void)> ipf;

      ipf.set<Functor, functor_static>();

      ipf();

      CHECK(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_member_reference_run_time)
    {
      Object object;
      etl::inplace_function<void(const Data&, int)> ipf;

      ipf.set(&Object::member_reference, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Reference_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_member_reference_compile_time)
    {
      Object object;
      etl::inplace_function<void(const Data&, int)> ipf;

      ipf.set(&Object::member_reference, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Reference_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_member_reference_const_run_time)
    {
      const Object object;
      etl::inplace_function<void(const Data&, int)> ipf;

      ipf.set(&Object::member_reference_const, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Reference_Const_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_set_member_reference_const_compile_time)
    {
      const Object object;
      etl::inplace_function<void(const Data&, int)> ipf;

      ipf.set(&Object::member_reference_const, object);

      Data data;
      data.ipf = VALUE1;

      ipf(data, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Reference_Const_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_copy_construct_run_time_contruction)
    {
      Object object;

      auto d1 = etl::inplace_function<int(int, int)>(&Object::member_int, object);
      auto d2(d1);

      d2(VALUE1, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK(function_called == FunctionCalled::Member_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_copy_construct_compile_time_contruction)
    {
      auto d1 = etl::inplace_function<int(int, int)>::create<Object, &Object::member_int, object_static>();
      auto d2(d1);

      d2(VALUE1, VALUE2);

      CHECK(function_called == FunctionCalled::Member_Int_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_copy_construct_different_size)
    {
      auto d1 = etl::inplace_function<void(int, int),  8, 16>(free_int);
      auto d2 = etl::inplace_function<void(int, int), 16, 16>(free_int);
      auto d3 = etl::inplace_function<void(int, int), 16,  8>(free_int);
      auto d4 = etl::inplace_function<void(int, int),  8,  8>(free_int);

      // These should not trigger any static asserts.
      decltype(d1) d1_1_copy(d1);
      decltype(d1) d1_4_copy(d4);

      decltype(d2) d2_1_copy(d1);
      decltype(d2) d2_2_copy(d2);

      decltype(d3) d3_3_copy(d3);
      decltype(d3) d3_4_copy(d4);

      CHECK_EQUAL(d1.size(), d1_1_copy.size());
      CHECK_EQUAL(d1.alignment(), d1_1_copy.alignment());

      CHECK_EQUAL(d1.size(), d1_4_copy.size());
      CHECK_EQUAL(d1.alignment(), d1_4_copy.alignment());

      CHECK_EQUAL(d2.size(), d2_1_copy.size());
      CHECK_EQUAL(d2.alignment(), d2_1_copy.alignment());

      CHECK_EQUAL(d2.size(), d2_2_copy.size());
      CHECK_EQUAL(d2.alignment(), d2_2_copy.alignment());

      CHECK_EQUAL(d3.size(), d3_3_copy.size());
      CHECK_EQUAL(d3.alignment(), d3_3_copy.alignment());

      CHECK_EQUAL(d3.size(), d3_4_copy.size());
      CHECK_EQUAL(d3.alignment(), d3_4_copy.alignment());
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_copy_assignment)
    {
      DestructibleMovableObject object;

      auto d1 = etl::inplace_function<void(int, int)>(object);
      etl::inplace_function<void(int, int)> d2;

      d2 = d1;

      d2(VALUE1, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK_TRUE(DestructibleMovableObject::function_operator_called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_move_assignment)
    {
      DestructibleMovableObject object;

      auto d1 = etl::inplace_function<void(int, int)>(object);
      etl::inplace_function<void(int, int)> d2;

      d2 = etl::move(d1);

      d2(VALUE1, VALUE2);

      CHECK_EQUAL(0, object.call_count);  // Ensure the original object is not modified.
      CHECK_TRUE(DestructibleMovableObject::function_operator_called);
    }

    //*************************************************************************
    TEST(test_vector_of_inplace_functions)
    {
      etl::vector<etl::inplace_function<int(int)>, 5> vector_of_inplace_functions;

      vector_of_inplace_functions.push_back(etl::inplace_function<int(int)>::create<times_2>());

      CHECK_EQUAL(42, vector_of_inplace_functions.front()(21));
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_or_run_time_normal)
    {
      auto ipf = etl::inplace_function<int(int, int)>(normal);

      int result = ipf.call_or(alternative, VALUE1, VALUE2);

      CHECK_EQUAL(VALUE1 + VALUE2, result);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_or_run_time_alternative)
    {
      etl::inplace_function<int(int, int)> ipf;

      int result = ipf.call_or(alternative, VALUE1, VALUE2);

      CHECK_EQUAL(VALUE1 + VALUE2 + 1, result);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_or_compile_time_alternative)
    {
      etl::inplace_function<int(int, int)> ipf;

      int result = ipf.call_or<alternative>(VALUE1, VALUE2);

      CHECK_EQUAL(VALUE1 + VALUE2 + 1, result);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_or_inplace_function_alternative)
    {
      etl::inplace_function<int(int, int)> ipf;

      auto alt = etl::inplace_function<int(int, int)>::create<alternative>();

      int result = ipf.call_or(alt, VALUE1, VALUE2);

      CHECK_EQUAL(VALUE1 + VALUE2 + 1, result);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_if_and_valid)
    {
      auto ipf = etl::inplace_function<int(int, int)>::create<normal>();

      etl::optional<int> result = ipf.call_if(VALUE1, VALUE2);

      CHECK(bool(result));
      CHECK_EQUAL(VALUE1 + VALUE2, result.value());
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_if_and_not_valid)
    {
      etl::inplace_function<int(int, int)> ipf;

      etl::optional<int> result = ipf.call_if(VALUE1, VALUE2);

      CHECK(!bool(result));
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_if_and_valid_returning_void)
    {
      auto ipf = etl::inplace_function<void(int, int)>::create<normal_returning_void>();

      bool was_called = ipf.call_if(VALUE1, VALUE2);

      CHECK(was_called);
      CHECK(function_called == FunctionCalled::Normal_Returning_Void_Called);
      CHECK(parameter_correct);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_call_if_and_not_valid_returning_void)
    {
      etl::inplace_function<void(int, int)> ipf;

      bool was_called = ipf.call_if(VALUE1, VALUE2);

      CHECK(!was_called);
      CHECK(function_called == FunctionCalled::Not_Called);
      CHECK(!parameter_correct);
    }
    
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_inplace_function_for)
    {
      FunctorSized<32> functor32;

      auto ipf = etl::inplace_function_for<int(void), decltype(functor32)>(functor32);

      int size = 0;

      function_called = FunctionCalled::Not_Called;
      size = ipf();
      CHECK_EQUAL(functor32.size(), size);
      CHECK_TRUE(function_called == FunctionCalled::Operator_Called);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_inplace_function_for_any)
    {
      FunctorSized<8>  functor8;
      FunctorSized<16> functor16;
      FunctorSized<32> functor32;

      auto ipf = etl::inplace_function_for_any<int(void), FunctorSized<8>, FunctorSized<16>, FunctorSized<32>>();
      int size = 0;

      function_called = FunctionCalled::Not_Called;
      ipf.set(functor8);
      size = ipf();
      CHECK_TRUE(function_called == FunctionCalled::Operator_Called);
      CHECK_EQUAL(functor8.size(), size);

      function_called = FunctionCalled::Not_Called;
      ipf.set(functor16);
      size = ipf();
      CHECK_TRUE(function_called == FunctionCalled::Operator_Called);
      CHECK_EQUAL(functor16.size(), size);
      
      function_called = FunctionCalled::Not_Called;
      ipf.set(functor32);
      size = ipf();
      CHECK_TRUE(function_called == FunctionCalled::Operator_Called);
      CHECK_EQUAL(functor32.size(), size);
    }

    //*************************************************************************
    TEST(make_inplace_function_from_free_function_name)
    {
      // Create from function name (decays to function pointer)
      auto ipf = etl::make_inplace_function<int(int, int)>(&free_int_return);

      CHECK_TRUE(bool(ipf));
      CHECK_EQUAL(7, ipf(3, 4));
    }

    //*************************************************************************
    TEST(make_inplace_function_from_free_function_pointer_variable)
    {
      // Create from explicit function pointer variable
      int (*fp)(int, int) = &free_int_return;

      auto ipf = etl::make_inplace_function<int(int, int)>(fp);

      CHECK_TRUE(ipf.is_valid());
      CHECK_EQUAL(13, ipf(6, 7));
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_assignment_to_an_ipf_of_function_over_a_lambda_and_back)
    {
      etl::inplace_function<int(int i, int j)> ipf;

      int value = 1;
      auto lambda = [value](int i, int j) -> int { return value + i + j; };

      int result = 0;

      ipf = lambda;
      result = ipf(2, 3);
      CHECK_EQUAL(1 + 2 + 3, result);

      ipf = normal;
      result = ipf(3, 4);
      CHECK_EQUAL(3 + 4, result);

      ipf = lambda;
      result = ipf(5, 6);
      CHECK_EQUAL(1 + 5 + 6, result);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_swap_valid_valid)
    {
      Object object;

      // ipf1 -> normal, ipf2 -> member_int
      etl::inplace_function<int(int, int)> ipf1(normal);
      etl::inplace_function<int(int, int)> ipf2(&Object::member_int, object);

      int r1_before = ipf1(VALUE1, VALUE2);
      int r2_before = ipf2(VALUE1, VALUE2);
      CHECK_EQUAL(VALUE1 + VALUE2,     r1_before);
      CHECK_EQUAL(VALUE1 + VALUE2 + 1, r2_before);

      swap(ipf1, ipf2); // ADL swap uses member swap

      int r1_after = ipf1(VALUE1, VALUE2);
      int r2_after = ipf2(VALUE1, VALUE2);
      // After swap ipf1 should now hold 'member_int', ipf2 should hold 'normal'
      CHECK_EQUAL(VALUE1 + VALUE2 + 1, r1_after);
      CHECK_EQUAL(VALUE1 + VALUE2,     r2_after);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_swap_valid_empty)
    {
      etl::inplace_function<int(int, int)> ipf_valid(normal);
      etl::inplace_function<int(int, int)> ipf_empty; // default constructed

      CHECK_TRUE(ipf_valid.is_valid());
      CHECK_FALSE(ipf_empty.is_valid());

      swap(ipf_valid, ipf_empty);

      // ipf_valid should now be empty, ipf_empty should now have 'normal'
      CHECK_FALSE(ipf_valid.is_valid());
      CHECK_TRUE(ipf_empty.is_valid());

      CHECK_EQUAL(VALUE1 + VALUE2, ipf_empty(VALUE1, VALUE2));
      CHECK_THROW(ipf_valid(VALUE1, VALUE2), etl::inplace_function_uninitialized);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_swap_empty_empty)
    {
      etl::inplace_function<int(int, int)> ipf_empty1; // default constructed
      etl::inplace_function<int(int, int)> ipf_empty2; // default constructed

      CHECK_FALSE(ipf_empty1.is_valid());
      CHECK_FALSE(ipf_empty2.is_valid());

      swap(ipf_empty1, ipf_empty2);

      // Both should still be empty
      CHECK_FALSE(ipf_empty1.is_valid());
      CHECK_FALSE(ipf_empty2.is_valid());
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_swap_self_noop)
    {
      etl::inplace_function<int(int, int)> ipf(normal);
      int before = ipf(VALUE1, VALUE2);
      ipf.swap(ipf); // self-swap should be a no-op
      int after  = ipf(VALUE1, VALUE2);
      CHECK_EQUAL(before, after);
      CHECK_EQUAL(VALUE1 + VALUE2, after);
    }

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_swap_runtime_functor_and_function)
    {
      struct PlusOne
      {
        int operator()(int a, int b) { return a + b + 1; }
      } functor;

      etl::inplace_function<int(int, int)> ipf_functor(functor);
      etl::inplace_function<int(int, int)> ipf_function(normal);

      CHECK_EQUAL(VALUE1 + VALUE2 + 1, ipf_functor(VALUE1, VALUE2));
      CHECK_EQUAL(VALUE1 + VALUE2,     ipf_function(VALUE1, VALUE2));

      ipf_functor.swap(ipf_function);

      CHECK_EQUAL(VALUE1 + VALUE2,     ipf_functor(VALUE1, VALUE2));     // now holds 'normal'
      CHECK_EQUAL(VALUE1 + VALUE2 + 1, ipf_function(VALUE1, VALUE2));    // now holds functor
    }

#if defined(ETL_NEGATIVE_TEST_INPLACE_FUNCTION_BAD_RETURN)
    //*************************************************************************
    // Triggers: return type not convertible (void -> int)
    TEST(test_inplace_function_static_assert_bad_return)
    {
      auto bad = [](int) { /* returns void */ };
      // static_assert in lambda_stub/const_lambda_stub should trigger:
      // "etl::inplace_function: bound lambda/functor is not compatible with the inplace_function signature"
      auto ipf = etl::inplace_function<int(int)>(bad);
      (void)ipf;
    }
#endif

#if defined(ETL_NEGATIVE_TEST_INPLACE_FUNCTION_RVALUE_PARAM_MISMATCH_NONCONST)
    //*************************************************************************
    // Triggers: parameter ref-qualification mismatch (expects rvalue, lambda takes lvalue ref)
    TEST(test_inplace_function_static_assert_param_mismatch_nonconst)
    {
      auto bad = [](int&) { /* needs lvalue */ };
      // Not invocable with int&&, so is_compatible_callable is false, so static_assert triggers
      auto ipf = etl::inplace_function<void(int&&)>(bad);
      (void)ipf;
    }
#endif

#if defined(ETL_NEGATIVE_TEST_INPLACE_FUNCTION_RVALUE_PARAM_MISMATCH_CONST)
    //*************************************************************************
    // Same as above, but binds a const lambda to hit const_lambda_stub
    TEST(test_inplace_function_static_assert_param_mismatch_const)
    {
      const auto bad = [](int&) { /* needs lvalue */ };
      // Not invocable with int&&, so is_compatible_callable is false, so static_assert triggers
      auto ipf = etl::inplace_function<void(int&&)>(bad);
      (void)ipf;
    }
#endif
  }
}