c – 如何实施尺寸有限的类似stl的容器？

编辑：具有私有继承的解决方案的草图

template <typename T,unsigned int N>
class fixed_vector : std::vector<T>
{
    typedef std::vector<T> vector_type;
public:
    typedef typename vector_type::reference reference;
    typedef typename vector_type::const_reference const_reference;
    typedef typename vector_type::iterator iterator;
    typedef typename vector_type::const_iterator const_iterator;
    typedef typename vector_type::value_type value_type;
    typedef typename vector_type::size_type size_type;

    fixed_vector() : vector_type() {}
    fixed_vector( size_type size,value_type const & value = value_type() )
       : vector_type(size,value)
    {}      

    void push_back( value_type v ) {
        ensure_can_grow();
        vector_type::push_back( v );
    }
    iterator insert( iterator position,value_type const & v ) {
        ensure_can_grow();
        vector_type::insert( position,v );
    }
    void reserve( size_type size ) {
        if ( size > N ) throw std::invalid_argument();
        vector_type::reserve( size );
    }
    size_type capacity() const {
        // In case the default implementation acquires by default 
        // more than N elements,or the vector grows to a higher capacity
        return std::min( vector_type::capacity(),N );
    }
    // provide other insert methods if required,with the same pattern
    using vector_type::begin;
    using vector_type::end;
    using vector_type::operator[];
    using vector_type::erase;
    using vector_type::size;
    using vector_type::empty;
private:
    void ensure_can_grow() const {
        // probably a different exception would make sense here: 
        if ( this->size() == N ) throw std::bad_alloc();
    }
};

那里有相当多的挥手… std :: vector需要更多可以添加到fa?ade的参数.如果您需要任何其他方法或typedef,您可以使用using声明将它们放入范围,重新定义typedef,或者使用您的特定测试实现适配器.

此外,在此实现中,size是编译时常量,但将其修改为构造函数参数非常简单.