[range.access.crbegin]

# 25 Ranges library [[ranges]](./#ranges)

## 25.3 Range access [[range.access]](range.access#crbegin)

### 25.3.8 ranges​::​crbegin [range.access.crbegin]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L965)

The name ranges​::​crbegin denotes a customization point
object ([[customization.point.object]](customization.point.object "16.3.3.3.5 Customization Point Object types"))[.](#1.sentence-1)

Given a subexpression E with type T,
let t be an lvalue that denotes the reified object for E[.](#1.sentence-2)

Then:

- [(1.1)](#1.1)

  If E is an rvalue andenable_borrowed_range<remove_cv_t<T>> is false,ranges​::​crbegin(E) is ill-formed[.](#1.1.sentence-1)

- [(1.2)](#1.2)

  Otherwise,
let U be ranges​::​rbegin(*possibly-const-range*(t))[.](#1.2.sentence-1)
  ranges​::​crbegin(E) is expression-equivalent toconst_iterator<decltype(U)>(U)[.](#1.2.sentence-2)

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L983)

[*Note [1](#note-1)*:

Whenever ranges​::​crbegin(E) is a valid expression, its
type models [input_or_output_iterator](iterator.concept.iterator#concept:input_or_output_iterator "24.3.4.6 Concept input_­or_­output_­iterator [iterator.concept.iterator]") and[*constant-iterator*](const.iterators.alias#concept:constant-iterator "24.5.3.2 Alias templates [const.iterators.alias]")[.](#2.sentence-1)

â *end note*]
