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4546. Integer-class type should be structural type

Section: 24.3.4.4 [iterator.concept.winc] Status: Ready Submitter: Hewill Kang Opened: 2026-03-19 Last modified: 2026-07-31

Priority: 3

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Discussion:

Currently, integer-class types are not guaranteed to be structural types, so the range of size members that return integer-class types may not be able to model tiny-range, because its size value cannot be used as a template argument even if it is a constant expression. This does not appear to be the intention.

Given that integer-class types should behave like regular integers, and those types in MSVC-STL and libstdc++ are both implemented as structural types, it would be better to be clear about the wording.

[2026-05-29; Reflector poll.]

Set priority to 3 after reflector poll.

Need additional statement clarifying when the types are template-argument-equivalent.

[2026-07-30; Tim provides new wording]

[2026-07-31 LWG telecon; Status changed: New → Ready.]

Proposed resolution:

This wording is relative to N5054.

1. Modify 24.3.4.4 [iterator.concept.winc] as indicated:

   -9- All integer-class types are structural types (13.2 [temp.param]) that model regular (18.6 [concepts.object]) and three_way_comparable<strong_ordering> (17.12.4 [cmp.concept]). Two values of an integer-class type are template-argument-equivalent if and only if they are equal.