清除单map（非嵌套map）

#include<map>
#include<string>
#include<iostream>
using namespace std;

int main()
{
	map<int, string> m_in;
    map<int,string>::iterator it_m_in;
    m_in[1]= "1111111111111111";
    m_in[2]= "2222222222222222";
    m_in[3]= "3333333333333333";
    m_in[4]= "4444444444444444";
    m_in[0]= "5555555555555555";

	for(it_m_in = m_in.begin(); it_m_in!=m_in.end();)
	{
		cout<<"    "<<it_m_in->first<<" --> "<<it_m_in->second<<"\n";
		m_in.erase(it_m_in++);
	}
	cout<<endl;
    return   0;
}

清除嵌套map

#include<map>
#include<string>
#include<iostream>
using namespace std;

int main()
{
	map<int, string> m_in;
    map<int,string>::iterator it_m_in;
    map<int, map<int, string>> m;
	map<int, map<int, string>>::iterator it_m;
    m_in[1]= "1111111111111111";
    m_in[2]= "2222222222222222";
    m_in[3]= "3333333333333333";
    m_in[4]= "4444444444444444";
    m_in[0]= "5555555555555555";
	m[11] = m_in;

    for(it_m=m.begin();it_m!=m.end();)
    {
		cout<<"key: "<<it_m->first <<"\n  value: \n";
		for(it_m_in = m_in.begin(); it_m_in!=m_in.end();)
		{
			cout<<"    "<<it_m_in->first<<" --> "<<it_m_in->second<<"\n";
			m_in.erase(it_m_in++);
		}
		cout<<endl;
        m.erase(it_m++);
    }
    return   0;
}

总结

嵌套map要一步一步删除。