Exotic casts

Here I will mention the non-conventional casts used in Karma.

static_pointer_cast

This is a cast for smart pointers. For example see here

void VulkanVertexArray::SetIndexBuffer(const std::shared_ptr<IndexBuffer>& indexBuffer)
{
	indexBuffer->Bind();

	m_IndexBuffer = std::static_pointer_cast<VulkanIndexBuffer>(indexBuffer);

	GenerateVulkanVA();
}

Note the Unreal Engine style of casting which doesn't use * for casting.

reinterpret_cast

This cast is used to convert a pointer of certain data-type into the pointer of any other data-type. An example can be found here

VkShaderModule VulkanVertexArray::CreateShaderModule(const std::vector<char>& code)
{
	VkShaderModuleCreateInfo createInfo{};
	createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
	createInfo.codeSize = code.size();
	createInfo.pCode = reinterpret_cast<const uint32_t*>(code.data());

	VkShaderModule shaderModule;
	VkResult result = vkCreateShaderModule(m_device, &createInfo, nullptr, &shaderModule);

	KR_CORE_ASSERT(result == VK_SUCCESS, "Failed to create shader module!");

	return shaderModule;
}

The createInfo.pCode pointer is of the type uint32_t. For more information see here page 106.

---

A crash course on difference between static_cast and dynamic_cast. dynamic_cast is a runtime cast which is used for only for polymorphic types. For example consider

class Base
{
public:
	virtual void test()
	{
	}
};

class Child : public Base
{
public:
	virtual void test() override
	{
	}
};

int main()
{
	Base* base = new Child();
	Child* ch = dynamic_cast<Child*>(base);

	if (ch)
	{
		std::cout << "Success for dynamic_cast";
	}

	delete base;
}

Here Child and Base are polymorphic types. Now consider the example for static_cast

class Base
{
};

class Child : public Base
{
};

int main()
{
	Base* base = new Child();
	Child* ch = static_cast<Child*>(base);

	if (ch)
	{
		std::cout << "Success for static_cast";
	}

	delete base;
}

Note that static_cast can be used for polymorphic types too. For more information read the answers here.

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A crash-course on C/C++ pointer gymnastics.