NextChainBuilder.h

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#pragma once
#include <type_traits>
#include <vulkan/vulkan_core.h>

namespace Vulkan {
    class ChainBuilder {
        public:
        ChainBuilder() : head(nullptr), tail(nullptr) {};
 
        template<typename VulkanStruct>
        ChainBuilder& add(VulkanStruct &object);
 
        template<typename T>
        T* getHead() {
            return head;
        }
 
        void* getHead() {
            return head;
        }
 
    private:
 
        struct BaseChain {
            VkStructureType sType;
            void* pNext;
        };
 
        template<typename T, typename = void>
        struct has_pNext : std::false_type {};
 
        template<typename T>
        struct has_pNext<T, std::void_t<decltype(std::declval<T>().pNext)>> : std::true_type {};
 
        void* head;
        void* tail;
 
    };
 
    template<typename VulkanStruct>
    ChainBuilder & ChainBuilder::add(VulkanStruct &object) {
        static_assert(has_pNext<VulkanStruct>::value, "Type must have pNext member");
 
        object.pNext = nullptr;
 
        if (!head) {
            head = &object;
            tail = &object;
        } else {
            static_cast<BaseChain*>(tail)->pNext = &object;
            tail = &object;
        }
        return *this;
    }
}