Class list

src/fl/stl/list.h:21–671

/// @tparam T The type of elements stored in the list
template <typename T>
class list {
private:
    struct Node {
        T data;
        Node* next;
        Node* prev;

        template<typename... Args>
        Node(Args&&... args) : data(fl::forward<Args>(args)...), next(nullptr), prev(nullptr) {}
    };

    Node* mHead;  // Sentinel node (circular list)
    fl::size mSize;
    memory_resource* mResource = default_memory_resource();

    void init_sentinel() {
        mHead = static_cast<Node*>(mResource->allocate(sizeof(Node)));
        mHead->next = mHead;
        mHead->prev = mHead;
        mSize = 0;
    }

    void destroy_sentinel() {
        if (mHead) {
            mResource->deallocate(mHead, sizeof(Node));
            mHead = nullptr;
        }
    }

    Node* create_node(const T& value) {
        Node* node = static_cast<Node*>(mResource->allocate(sizeof(Node)));
        new (node) Node(value);
        return node;
    }

    Node* create_node(T&& value) {
        Node* node = static_cast<Node*>(mResource->allocate(sizeof(Node)));
        new (node) Node(fl::move(value));
        return node;
    }

    void destroy_node(Node* node) {
        if (node && node != mHead) {
            node->~Node();
            mResource->deallocate(node, sizeof(Node));
        }
    }

    void link_before(Node* pos, Node* node) {
        node->next = pos;
        node->prev = pos->prev;
        pos->prev->next = node;
        pos->prev = node;
    }

    void unlink(Node* node) {
        node->prev->next = node->next;
        node->next->prev = node->prev;