[Interest] How to make QMap work as input to std::ranges::views?

[Schimkowitsch Robert]

> Il 14/04/25 17:35, Volker Hilsheimer via Interest ha scritto:
> > As Thiago says, you have to use std::views::transform.

Sorry, that was a typo. Corrected example using asKeyValueRange: https://godbolt.org/z/fT4G9TnKW

> In that case, you can put the QMap itself directly into the pipeline:
> >
> > auto viewAsPair = map | std::views::transform(fTransform);
> >

Passing the map directly only gives me the values, not the keys, see https://godbolt.org/z/jEahnWMT3

> But you cannot use an rvalue as the input range (see e.g.https://en.cppreference.com/w/cpp/ranges/dangling). Make a copy first:
>
>      auto keyValueRange = map.asKeyValueRange();
>      auto viewAsPair = keyValueRange | std::views::transform(fTransform);> >
> >      auto keyValueRange = map.asKeyValueRange();
> >      auto viewAsPair = keyValueRange |
> > std::views::transform(fTransform);
>
> This is a bug. The type returned asKeyValueRange() is supposed to model
> ranges::view. It doesn't; it doesn't inherit from view_interface nor has
> enabled_view enabled for it, and it doesn't model std::moveable. This should
> be a subtask of QTBUG-105465.

I tend to agree.

Kind regards

Robert
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