On 2023-10-02 at 11:33, Aaron Gray via Std-Discussion wrote:
> I am trying to work out how to do a :-
>
> std::unordered_map<std::pair<const Type *, const Type*>, bool,
> std::hash<Type>> subTypeMemorization;
>
> Given a barebones class Type :-
>
> class Type {
> public:
> std::string name;
> ....
> };
>
> Godbolt attempted example :-
>
> https://godbolt.org/z/r4YrG841E
>

The hash should not be for 'Type', but for the whole key
'std::pair<const Type *, const Type*>'.

And, BTW, doesn't mapping to a bool look very similar to a set?