容器set find

// set::find
#include <iostream>
#include <set>

int main ()
{
std::set<int> myset;
std::set<int>::iterator it;

// set some initial values:
for (int i=1; i<=5; i++) myset.insert(i*10);    // set: 10 20 30 40 50

it=myset.find(20);
myset.erase (it);
myset.erase (myset.find(40));

std::cout << "myset contains:";
for (it=myset.begin(); it!=myset.end(); ++it)
std::cout << ' ' << *it;
std::cout << '\n';

return 0;
}

myset contains: 10 30 50

set<A> si;

si.clear(); //清空set