Smart Pointers & Memory Management

#include 
#include 

// Static pool: 16 × CanFrame_t objects
struct CanFrame_t { uint8_t data[8]; uint16_t id; uint8_t dlc; };

class CanFramePool {
public:
    static constexpr std::size_t POOL_SIZE = 16u;

    static CanFrame_t* alloc() noexcept {
        for (auto &slot : s_pool) {
            if (!slot.in_use) { slot.in_use = true; return &slot.frame; }
        }
        return nullptr;  // pool exhausted
    }

    static void free(CanFrame_t *p) noexcept {
        for (auto &slot : s_pool) {
            if (&slot.frame == p) { slot.in_use = false; return; }
        }
    }

private:
    struct Slot { CanFrame_t frame; bool in_use = false; };
    static std::array s_pool;
};

// Custom deleter: returns frame to pool on unique_ptr destruction
struct CanFrameDeleter {
    void operator()(CanFrame_t *p) const noexcept { CanFramePool::free(p); }
};

using CanFramePtr = std::unique_ptr;

// Factory function: allocate with automatic pool return
CanFramePtr make_can_frame() noexcept {
    return CanFramePtr{CanFramePool::alloc()};
}

// Usage: frame automatically returned to pool when it goes out of scope
void process_message() {
    auto frame = make_can_frame();
    if (!frame) { return; }  // pool exhausted
    frame->id = 0x200u;
    frame->dlc = 2u;
    Can_Send(*frame);
    // ~unique_ptr: returns frame to pool — no manual free needed
}