c语言error c2679,这个异常如何解决，error C2679: binary '<<'

C/C++ code#include

#include

#include

#include

#include

using namespace std;

typedef map months_type;

namespace std

{

template

ostream& operator< &p)

{

cout<

return out;

}

ostream& operator<

{

copy(l.begin(), l.end(), ostream_iterator<:value_type>(out, ";\n"));

return out;

}

}

void main()

{

months_type months;

typedef months_type::value_type value_type;

months.insert(value_type(string("January"),31));

months.insert(value_type(string("February"),28));

months.insert(value_type(string("April"),30));

months.insert(value_type(string("March"),31));

cout<

}