I need an array where size is known at compile time. I know I can use std::vector or boost::array. But that's doesn't teach me how it works internally. Also I couldn't find how to add items into boost::array other than using the initializer. I have written the following code for a generic array. My intention is to get familiar with iterators, template specializations etc. Following is the code

我需要一个在编译时已知大小的数组。我知道我可以使用std :: vector或boost :: array。但这并没有教我如何在内部工作。除了使用初始化程序之外,我找不到如何将项添加到boost :: array中。我为通用数组编写了以下代码。我的目的是熟悉迭代器,模板特化等。以下是代码

template<typename T>
struct iterator_traits
{
    typedef T           value_type;
    typedef T&          reference_type;
    typedef T*          iterator;
    typedef const T*    const_iterator;
    typedef std::reverse_iterator<iterator> reverse_iterator;
};

template<typename T>
struct iterator_traits<T*>
{
    typedef T*          value_type;
    typedef T*&         reference_type;
    typedef T**         iterator;
    typedef const T     const_iterator;
    typedef std::reverse_iterator<iterator> reverse_iterator;
};

template<typename T, size_t size = 10>
class Array
{
    public:

        typedef typename iterator_traits<T>::value_type       value_type;
        typedef typename iterator_traits<T>::reference_type   reference_type;
        typedef typename iterator_traits<T>::iterator         iterator;
        typedef typename iterator_traits<T>::const_iterator   const_iterator;
        typedef typename iterator_traits<T>::reverse_iterator reverse_iterator;

        Array() : lastIndex(0) {
        }

        void add(value_type element) {
            if(lastIndex >= size)
                throw std::out_of_range("Array is full");
            array_[lastIndex++] = element;
        }

        reference_type at(unsigned int index){
            if(index < size)
                return array_[index];
            else
                throw std::out_of_range("Invalid index");
        }

        size_t capacity(){
            return size;
        }

        iterator begin(){
            return array_;
        }

        iterator end(){
            return array_ + size;
        }

        const_iterator begin() const{
            return array_;
        }

        const_iterator end() const{
            return array_ + size;
        }

        reverse_iterator rbegin() {
            return reverse_iterator(end());
        }

        reverse_iterator rend() {
            return reverse_iterator(begin());
        }

    private:

        value_type array_[size];
        unsigned int lastIndex;
};

The above code works well. Following are my questions

上面的代码效果很好。以下是我的问题

1 - How can I create my array like boost::array does? Something like

1 - 如何像boost :: array一样创建我的数组?就像是

Array<int> ints = { 10, 12 };

2 - Are there any pitfalls in the code?

2 - 代码中是否存在任何缺陷?

3 - I had to use a specialization for pointer types in traits. Is that the best practice?

3 - 我必须对特征中的指针类型使用特化。这是最好的做法吗?

4 - Iterator pattern is implemented correctly or not?

4 - 迭代器模式是否正确实现?

Any thoughts would be great!

任何想法都会很棒!

3 个解决方案

Array<int> ints = { 10, 12 };

    // type definitions
    typedef T              value_type;
    typedef T*             iterator;
    typedef const T*       const_iterator;
    typedef T&             reference;
    typedef const T&       const_reference;
    typedef std::size_t    size_type;
    typedef std::ptrdiff_t difference_type;