safe_int, constrained, their error policies, and the safe_iN aliases are
non-framework add-ons, so their public names move out of mp_units into the
mp_units::utility extension tier (next to the representation concepts already
there). The headers move to core/include/mp-units/utility/ accordingly but stay
in the core component: safe_int reuses the core 128-bit integer toolkit
(integral, is_signed_v, int128_t, ...) that also backs the scaling engine, so it
bridges to mp_units::detail with a single using-directive rather than relocating
or duplicating that toolkit. overflow_policies stays framework (it backs bounded
quantity point origins). No deprecation shims: these types are unreleased.
Also fixes utility/representation.h, whose public concepts delegated via the
unqualified detail::X. That resolved to mp_units::detail only as long as
mp_units::utility::detail did not exist; now that constrained/safe_int introduce
it, the references are qualified to ::mp_units::detail:: so they stay
order-independent (this surfaced only in the module build).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Replace the `disable_vector`/`disable_tensor` opt-outs with intrinsic,
adapter-overridable traits and split representation classification into two tiers.
- `customization_points.h` now owns the customizable surface: the `real`/`imag`/
`modulus` CPOs plus the `numeric_field` (field axis) and `tensor_order` (order
axis) traits. Adapters specialize these; the derived concepts stay with the
rest of the concept model in `representation_concepts.h`.
- `numeric_field` is the single source of truth for the field axis (default:
`real()`/`imag()` API detection). Field matching is exact and disjoint - a real
quantity needs a real representation and a complex one a complex representation.
- `tensor_order` is detected structurally (two-index access -> 2, one-index -> 1,
otherwise 0) and overridable. Order matching is rank-ordered: a lower-order
representation fills a higher-order slot.
- Character concepts (`Real`/`Complex`, rank-ordered `Scalar`/`Vector`/`Tensor`)
carry no representation-validity, so in V3 they can also classify a quantity by
its character. The `*Representation` concepts are `NotQuantity`-first + character
+ `UnitMagnitudeScalable`; leading with `NotQuantity` rejects a quantity before
its operators are instantiated, avoiding a constraint-satisfaction cycle.
- Eigen/Blaze adapters declare `numeric_field` from their element type (they expose
`real()`/`imag()` on real types too, which the API default would misread as complex).
- Rename `MagnitudeScalable` -> `UnitMagnitudeScalable` and `UsesMagnitudeAwareScaling`
-> `UsesUnitMagnitudeAwareScaling` to disambiguate scaling by a `unit_magnitude`
from the value/L2 magnitude (the `magnitude` CPO).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Replace `using enum quantity_character_legacy` plus bare character names in the ISQ/HEP
tests with local `quantity_character` constants (`scalar`, `complex_scalar`, `vector`,
`tensor`) built from `quantity_tensor_order` / `quantity_field`, and switch the
`RepresentationOf` / `QUANTITY_SPEC_` character arguments in the concept and quantity-spec
tests to the bare-axis spelling. `real_scalar` is renamed to `scalar` for consistency with
the order-named constants. `apparent_power` (derived from the complex `complex_power`)
pins `quantity_field::real`, matching the library definition.
This removes the final legacy-enum usage from the repository.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>