C++实现模板实现动态申请内存

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
template <typename T>
class Array
{
private:
	T* m_buffer;
	int m_capacity;
	int m_size;
public:
	Array(int capacity=4)
	{
		m_buffer = new T[capacity];
		m_capacity = capacity;
		m_size = 0;
	}
	void PushBack(T val)
	{
		if (m_size >= m_capacity)
		{
			Resize();
		}
		m_buffer[m_size] = val;
		m_size++;
	}
	int Capacity() {
		return m_capacity;
	}
	int Size() {
		return m_size;
	}
private:
	void Resize()
	{
		//创建一个更大的缓冲区
		int n = m_capacity + 4;
		T* buf = new T(n);

		//拷贝原有的内容
		memcpy(buf, m_buffer, m_capacity);

		//删除旧的内容，释放其内存
		delete[] m_buffer;

		//更新一下成员变量
		m_capacity = n;
		m_buffer = buf;
	}
};
int main()
{
	Array <int> a;
	a.PushBack(1);
	a.PushBack(2);
	a.PushBack(3);
	a.PushBack(4);
	a.PushBack(4);
	int size = a.Size();
	return 0;

}