c++中vector的使用和模拟实现

#include
#include
#include
using namespace std;
 
namespace myvector
{
	template
	class vector
	{
	public:
		typedef T* iterator;
 
		iterator begin()
		{
			return start;
		}
 
		iterator end()
		{
			return finish;
		}
 
		//默认构造函数
		vector()
			:start(nullptr)
			, finish(nullptr)
			, end_of_storage(nullptr)
		{}
		//容量
		size_t capacity()
		{
			return end_of_storage - start;
		}
 
		size_t size()
		{
			return finish - start;
		}
 
		void reserve(size_t n)
		{
			if (n > capacity())
			{
				//开新空间
				T* tmp = new T[n];
				//拷贝旧空间的内容
				memcpy(tmp, start, sizeof(T)*size());
				//改变容量
				finish = tmp + size();
				end_of_storage = tmp + n;
				//释放旧空间
				T* tmp1 = start;
				start = tmp;
				tmp = nullptr;
			}
		}
 
		void resize(size_t n, const T& val = T())
		{
			//判断容量
			if (n > capacity())
				reserve(n);
			//如果n= start && pos <= finish);
			size_t pos1 = pos - start;
			check_capacity();
			//解决迭代器失效
			pos = start + pos1;
			//移动数据
			iterator end = finish;
			while (end >= pos)
			{
				*(end + 1) = *end;
				end--;
			}
			//插入数据
			*pos = x;
			finish++;
			return pos;
		}
 
		//删除数据
		void pop_back()
		{
			assert(finish > start);
			finish--;
		}
		iterator erase(iterator pos)
		{
			assert(pos >= start && pos 

void test1()
{
	//测试默认构造和析构函数
	myvector::vector v1;
 
}
 
void test2()
{
	//测试push_back()、reserve、check_capacity、size、capacity
	myvector::vector v2;
 
	//插入至少五个数据，进行一次扩容，扩容间接对size和capacity以及check_capacity进行了测试
	v2.push_back(1);
	v2.push_back(2);
	v2.push_back(3);
	v2.push_back(4);
	//v2.push_back(5);
	for (size_t i = 0; i ::iterator it = v2.begin();
	it = v2.insert(it,0);
	it = v2.insert(it + 2, 10);
	for (size_t i = 0; i