lock free test

list.cpp

#include <stdio.h>
#include <atomic>

template<typename V>
class LockFreeList {
    struct Node {
        V value;
        std::shared_ptr<Node> next;
        Node(const V& value) : value(value), next(nullptr) {}
    };
    
    //std::atomic<std::shared_ptr<Node>> first; // waiting for C++20
    std::shared_ptr<Node> first;
    
public:
    void push_front(const V& value) {
        auto new_node = std::make_shared<Node>(value);
        new_node->next = std::atomic_load(&first);
        while(!std::atomic_compare_exchange_weak(&first, &new_node->next, new_node));
    }
    
    V pop_front() {
        auto node = std::atomic_load(&first);
        while (node && !std::atomic_compare_exchange_weak(&first, &node, node->next));
        return std::move(node->value);
   }
};