std::vector<T,Allocator>::begin, std::vector<T,Allocator>::cbegin

#include <iostream>
#include <vector>
#include <string>
 
int main()
{
	std::vector<int> ints {1, 2, 4, 8, 16};
	std::vector<std::string> fruits {"orange", "apple", "raspberry"};
	std::vector<char> empty;
 
	// 求和 vector ints 中的所有整数（若存在），仅打印结果。
	int sum = 0;
	for (auto it = ints.cbegin(); it != ints.cend(); it++)
		sum += *it;
	std::cout << "Sum of ints: " << sum << "\n";
 
	// 打印 vector fruits 中的首个水果，而不检查是否有一个。
	std::cout << "First fruit: " << *fruits.begin() << "\n";
 
	if (empty.begin() == empty.end())
		std::cout << "vector 'empty' is indeed empty.\n";
}