[mdspan.layout.policy.reqmts]

# 23 Containers library [[containers]](./#containers)

## 23.7 Views [[views]](views#mdspan.layout.policy.reqmts)

### 23.7.3 Multidimensional access [[views.multidim]](views.multidim#mdspan.layout.policy.reqmts)

#### 23.7.3.4 Layout mapping [[mdspan.layout]](mdspan.layout#policy.reqmts)

#### 23.7.3.4.3 Layout mapping policy requirements [mdspan.layout.policy.reqmts]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/containers.tex#L21866)

A type MP meets the [*layout mapping policy*](#def:layout_mapping_policy "23.7.3.4.3 Layout mapping policy requirements [mdspan.layout.policy.reqmts]") requirements
if for a type E that is a specialization of extents,MP​::​mapping<E> is valid and denotes a type X that meets the layout mapping requirements ([[mdspan.layout.reqmts]](mdspan.layout.reqmts "23.7.3.4.2 Requirements")), and
for which the [*qualified-id*](expr.prim.id.qual#nt:qualified-id "7.5.5.3 Qualified names [expr.prim.id.qual]") X​::​layout_type is valid and
denotes the type MP and
the [*qualified-id*](expr.prim.id.qual#nt:qualified-id "7.5.5.3 Qualified names [expr.prim.id.qual]") X​::​extents_type denotes E[.](#1.sentence-1)
