Encapsulate std::map to allow iterating, but no di

Question

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Prevent direct access to std::map keys (2 answers)

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Is there a way to encapsulate std::map within a user-defined class, allowing iteration, but not allowing direct access to the key?

I would like to manipulate the key upon insertion and I want to force all access to elements through a user-defined method (as the key will need to be modified).

I think the problem is allowing iterating over the map, whilst preventing the user from accessing the key via the iterator.

Answer 1

Do not expose iterators. Expose a for_each function that passes each element to the user-provided (lambda) function.

Alternatively, use a transform iterator.