How do I use custom allocators in C++11?

How do I use custom allocators in C++11?

In C++11, you can create a custom allocator by defining a class that implements the required methods like allocate and deallocate.

What methods do I need to implement in my custom allocator?

You need to implement at least the allocate, deallocate, and construct methods. Optionally, you can also implement the destroy method.

Can you give me an example of a simple custom allocator?

Sure! Here's a basic example:

template <typename T>
class MyAllocator {
public:
    using value_type = T;

    MyAllocator() = default;

    T* allocate(std::size_t n) {
        return static_cast<T*>(::operator new(n * sizeof(T)));
    }

    void deallocate(T* p, std::size_t) {
        ::operator delete(p);
    }
};

This allocator uses the global new and delete operators.

How do I use my custom allocator with STL containers?

You can use your custom allocator by specifying it as a template argument when declaring the STL container, like this:

std::vector<int, MyAllocator<int>> myVector;