pb_ds中的tree中，最小的数是否被视为第0小？

如以下代码：

#include<iostream>
#include<functional>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
__gnu_pbds::tree<int,__gnu_pbds::null_type,less<int>,__gnu_pbds::rb_tree_tag,__gnu_pbds::tree_order_statistics_node_update> rbt;
int main(){
	for(int i=1;i<=200;i++)rbt.insert(i);
	cout<<*(rbt.find_by_order(0))<<" "<<*(rbt.find_by_order(1))<<" "<<*(rbt.find_by_order(2));
	return 0;
}

输出的是

1 2 3