std::hash value on string value and not on memory address?

As stated in this link:

There is no specialization for C strings. std::hash produces a hash of the value of the pointer (the memory address), it does not examine the contents of any character array.

Which means that with the same string value, different hashcodes could be produced. For example, having this code:

//MOK and MOV are template arguments
void emit(MOK key, MOV value) {
    auto h = hash<MOK>()(key);
    cout<<"key="<<key<<" h="<<h<<endl;
    ...

This is the output produced by calling 4 times emit() on the same key (with MOK=string) value (but 4 different tokens/string objects):

key=hello h=140311481289184
key=hello h=140311414180320
key=hello h=140311414180326
key=hello h=140311481289190

How can I obtain the same hash code for std::string? I'd prefer not to use boost