On 2023-10-27 03:23, Smith, Jim via Std-Proposals wrote:
> Yes, I do mean the nodes of a data structure, for example, left or
> right node of a binary tree.
>
> So for example, if I wanted std::map to use my tree structure
> implementation certain features would be expected in my implementation
> that would allow std::map to use it, like a way to iterate over the
> nodes using accessible members and so on. That's what I meant by
> expected features.
>
> This would allow customization and additional features to be added by
> the developer and still use the standard library interface in code.

This sounds wierd.

The iteration and node structure is what typically defines the standard
containers and provides their guarantees.

I believe I have seen some mentions of explicit separation of storage
and algorithm for containers but I lack a reference for it.

If you just want better names for elements of a map you can use the
transparant comparator support in std::set (since c++14) to achieve
that.

struct element {
   int key;
   int value;
};
struct element_compare {
   typedef void is_transparent;
   bool cmp(int a, int b) { return a < b; }
   bool operator()(int a, int b) { return cmp(a, b); }
   bool operator()(int a, const element& b) { return cmp(a, b.key); }
   bool operator()(const element& a, int b) { return cmp(a.key, b); }
   bool operator()(const element& a, const element& b) { return
cmp(a.key, b.key); }
};

std::set<element, element_compare> mine;

/MF

>
> -- James S.
>
>
> ------- Original Message -------
> On Monday, September 18th, 2023 at 2:28 PM, Jason McKesson via
> Std-Proposals <std-proposals_at_[hidden]> wrote:
>
>
>> On Mon, Sep 18, 2023 at 1:52 PM Smith, Jim via Std-Proposals
>> std-proposals_at_[hidden] wrote:
>>
>> > Hi All,
>> >
>> > I would like to simply pass my data structure to its std c++ equivalent and have it construct from the given item or node.
>> >
>> > For example:
>> >
>> > auto& m = get_my_map();
>> > ...
>> >
>> > // Using type deduction here for m instead of passing to template would be
>> > std::map<int, std::string> m_map(m->node);
>> >
>> > so I'm proposing a constructor for the standard data structures that will take a node type from a given structure and use it to construct itself using existing nodes and expected features of the node type.
>> >
>> > Only the range constructors appear to be similar.
>>
>>
>> It is unclear to me what exactly you mean here. When you say "node
>> type", do you mean the actual `std::map::node_type` type? Or do you
>> mean "node type" in the vernacular sense of the term (some kind of
>> data structure with pointers to the other "nodes" in a graph of some
>> kind)?
>>
>> If it's the former, your request doesn't really make sense. The only
>> "expected features" of a `node_type` object are the ability to modify
>> both the key and value of the stored object and the ability to inject
>> it into a compatible container. There is no iteration functionality
>> that would allow it to get any "existing nodes" from a `node_type`.
>>
>> And if it's the latter, then you need to be more specific as to what
>> the "expected features" of this interface are intended to be.
>> --
>> Std-Proposals mailing list
>> Std-Proposals_at_[hidden]
>> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals