std::hash value on char* value and not on memory address?

Question

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 char* 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=char*) 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 char*? I'd prefer not to use boost

Answer 1

You can use std::collate::hash e.g. https://www.cplusplus.com/reference/locale/collate/hash/

Answer 2

In C++17 you should use std::hash<std::string_view> which works seamlessly since const char* can be implicitly converted to it.