c++，訪問控制，每次讀寫變量前如何檢查

Question

我試圖在調試模式下每當寫入或讀取值時進行檢查，以在發送前緩存數據競爭和其他線程錯誤。 該系統僅適用於調試模式，只能作為信息收集系統使用，因此在發布構建時沒有開銷。

須藤代碼：

template<T>
struct Resource
{
    /*
    Here I need to somehow do a check on all reads and writes?
    How would this class look if it just where to print "read" and "write",
    on their corresponding actions, and is this even possible?

    Edit: The resource class works like wrapper of another type,
    this means the it should also function as so. This can be achieved
    by overriding the &operator.

    Maybe there is something else that can be overwritten in order
    to intercept writes?
    */

    explicit operator T&() { return resource; }
}

class SomeType()
{
public:
    uint32_t GetSomething();
    uint32_t somethingElse;
}

Resource<SomeType> resource1;
Resource<SomeType> resource2;
Resource<SomeType> resource3;

AccessPolicy accessPolicy;
accessPolicy.AddResource(resource1, EAccessPolicy::Read);
accessPolicy.AddResource(resource2, EAccessPolicy::Write);

Task task = Task(&ExampleTask, accessPolicy);

static void ExampleTask()
{
    auto something = resource1.GetSomething(); // Allowed

    resource2 = SomeClass(); // Allowed
    resource2.somethingElse = 4;

    resource3.GetSomething(); // Unauthorized access assert
}

Answer 1

你的意思是這樣的嗎？

template<T>
struct Resource
{
    Resource(const T &value) { v = value; }
    T & GetSomething(Task & task) {
        if (task.is_allowed(EAccessPolicy::Read, this)) {
            std::cout << "read" << std::endl;
            return v;
        } else {
            // error
        }
    }
    void SetSomething(Task & task, const T & t) {
        if (task.is_allowed(EAccessPolicy::Write, this)) {
            std::cout << "write" << std::endl;
            v = t;
        } else {
            // error
        }
    }
private:
    T v;
}