[range.take.while.view]

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

## 25.7 Range adaptors [[range.adaptors]](range.adaptors#range.take.while.view)

### 25.7.11 Take while view [[range.take.while]](range.take.while#view)

#### 25.7.11.2 Class template take_while_view [range.take.while.view]

[ð](#lib:take_while_view)

namespace std::ranges {template<[view](range.view#concept:view "25.4.5 Views [range.view]") V, class Pred>requires [input_range](range.refinements#concept:input_range "25.4.6 Other range refinements [range.refinements]")<V> && is_object_v<Pred> &&[indirect_unary_predicate](indirectcallable.indirectinvocable#concept:indirect_unary_predicate "24.3.6.3 Indirect callables [indirectcallable.indirectinvocable]")<const Pred, iterator_t<V>>class take_while_view : public view_interface<take_while_view<V, Pred>> {// [[range.take.while.sentinel]](range.take.while.sentinel "25.7.11.3 Class template take_­while_­view​::​sentinel"), class template take_while_view​::​*sentinel*template<bool> class *sentinel*; // *exposition only* V *base_* = V(); // *exposition only**movable-box*<Pred> *pred_*; // *exposition only*public: take_while_view() requires [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")<V> && [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")<Pred> = default; constexpr explicit take_while_view(V base, Pred pred); constexpr V base() const & requires [copy_constructible](concept.copyconstructible#concept:copy_constructible "18.4.14 Concept copy_­constructible [concept.copyconstructible]")<V> { return *base_*; }constexpr V base() && { return std::move(*base_*); }constexpr const Pred& pred() const; constexpr auto begin() requires (![*simple-view*](range.utility.helpers#concept:simple-view "25.5.2 Helper concepts [range.utility.helpers]")<V>){ return ranges::begin(*base_*); }constexpr auto begin() constrequires [range](range.range#concept:range "25.4.2 Ranges [range.range]")<const V> &&[indirect_unary_predicate](indirectcallable.indirectinvocable#concept:indirect_unary_predicate "24.3.6.3 Indirect callables [indirectcallable.indirectinvocable]")<const Pred, iterator_t<const V>>{ return ranges::begin(*base_*); }constexpr auto end() requires (![*simple-view*](range.utility.helpers#concept:simple-view "25.5.2 Helper concepts [range.utility.helpers]")<V>){ return *sentinel*<false>(ranges::end(*base_*), addressof(**pred_*)); }constexpr auto end() constrequires [range](range.range#concept:range "25.4.2 Ranges [range.range]")<const V> &&[indirect_unary_predicate](indirectcallable.indirectinvocable#concept:indirect_unary_predicate "24.3.6.3 Indirect callables [indirectcallable.indirectinvocable]")<const Pred, iterator_t<const V>>{ return *sentinel*<true>(ranges::end(*base_*), addressof(**pred_*)); }}; template<class R, class Pred> take_while_view(R&&, Pred) -> take_while_view<views::all_t<R>, Pred>;}

[ð](#lib:take_while_view,constructor)

`constexpr explicit take_while_view(V base, Pred pred);
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L6250)

*Effects*: Initializes *base_* with std​::​move(base) and*pred_* with std​::​move(pred)[.](#1.sentence-1)

[ð](#lib:pred,take_while_view)

`constexpr const Pred& pred() const;
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L6262)

*Effects*: Equivalent to: return **pred_*;
