C++ std::vector 基本用法2

#include <iostream>
#include <vector>

using namespace std;


int main() 
{
	int ar[10] = { 1,2,3,4,5,6,7,8,9,0 };
	std::vector<int> vec5(ar, ar + 10);

	// reverse
	size_t cap1 = vec5.capacity();	// = 10
	vec5.reserve(20);				// = Request a change in capacity
	size_t cap2 = vec5.capacity();	// = 20

	// data()
	int * pInt = vec5.data();
	for (size_t i=0; i<vec5.size(); ++i)
	{
		cout << pInt[i];
	}
	cout << endl; // 1234567890

	// begin end
	for (auto it=vec5.begin(); it != vec5.end(); ++it)
	{
		cout << *it;
	}
	cout << endl; // 1234567890

	// cbegin cend 常量，保证不改变 vector 中的元素
	for (auto it = vec5.cbegin(); it != vec5.cend(); ++it)
	{
		cout << *it;
	}
	cout << endl; // 1234567890

	// rbegin rend 注意偏移是 ++ 操作
	for (auto it = vec5.rbegin(); it != vec5.rend(); ++it)
	{
		cout << *it;
	}
	cout << endl; // 0987654321

	// iterator erase (const_iterator position);
	vec5.erase(vec5.begin()); // delete 1; size = 9

	// iterator erase (const_iterator first, const_iterator last);
	vec5.erase(vec5.begin(), vec5.begin()+2); // delete 2, 3; size = 7

	// max_size; Returns the maximum number of elements that the vector can hold.
	// 系统或者库的设计上线。并非机器所能申请的最大大小。
	size_t maxSize = vec5.max_size();

	std::vector<int> vec6(2);
	vec5.swap(vec6);					// 两者交换
	//vec5.swap(std::vector<int>());	// 2015支持，2017不支持

}