Result: A type that models copyable, and for which is_nothrow_move_constructible_v<A::data_handle_type> is true,is_nothrow_move_assignable_v<A::data_handle_type> is true, andis_nothrow_swappable_v<A::data_handle_type> is true.

[Note 1:

The type of data_handle_type need not be element_type*.

â end note]

typename A::reference

Result: A type that modelscommon_reference_with<A::reference&&, A::element_type&>.

[Note 2:

The type of reference need not be element_type&.

â end note]

typename A::offset_policy

Result: A type OP such that:

(5.1)

OP meets the accessor policy requirements,

(5.2)

constructible_from<OP, const A&> is modeled, and

(5.3)

is_same_v<typename OP::element_type, typename A::element_type> is true.

a.access(p, i)

Result: A::reference

Remarks: The expression is equality preserving.

[Note 3:

Concrete accessor policies can impose preconditions for their access function.

However, they might not.

For example, an accessor wherep is span<A::element_type, dynamic_extent> andaccess(p, i) returns p[i % p.size()] does not need to impose a precondition on i.

â end note]

a.offset(p, i)

Result: A::offset_policy::data_handle_type

Returns: q such that for b being A::offset_policy(a), and any integer n for which [0, n) is an accessible range of p and a:

(10.1)

[0,nâi) is an accessible range of q and b; and

(10.2)

b.access(q, j) provides access to the same element as a.access(p, i + j), for every j in the range [0,nâi).

Remarks: The expression is equality-preserving.

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23 Containers library [containers]

23.7 Views [views]

23.7.3 Multidimensional access [views.multidim]

23.7.3.5 Accessor policy [mdspan.accessor]

23.7.3.5.2 Requirements [mdspan.accessor.reqmts]

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