[uninitialized.construct.default]

# 26 Algorithms library [[algorithms]](./#algorithms)

## 26.11 Specialized <memory> algorithms [[specialized.algorithms]](specialized.algorithms#uninitialized.construct.default)

### 26.11.3 uninitialized_default_construct [uninitialized.construct.default]

[🔗](#lib:uninitialized_default_construct)

`template<class NoThrowForwardIterator>
  constexpr void uninitialized_default_construct(NoThrowForwardIterator first,
                                                 NoThrowForwardIterator last);
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L13718)

*Effects*: Equivalent to:for (; first != last; ++first)::new (*voidify*(*first))typename iterator_traits<NoThrowForwardIterator>::value_type;

[🔗](#lib:uninitialized_default_construct_)

`namespace ranges {
  template<[nothrow-forward-iterator](special.mem.concepts#concept:nothrow-forward-iterator "26.11.2 Special memory concepts [special.mem.concepts]") I, [nothrow-sentinel-for](special.mem.concepts#concept:nothrow-sentinel-for "26.11.2 Special memory concepts [special.mem.concepts]")<I> S>
    requires [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")<iter_value_t<I>>
    constexpr I uninitialized_default_construct(I first, S last);
  template<[nothrow-forward-range](special.mem.concepts#concept:nothrow-forward-range "26.11.2 Special memory concepts [special.mem.concepts]") R>
    requires [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")<range_value_t<R>>
    constexpr borrowed_iterator_t<R> uninitialized_default_construct(R&& r);
}
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L13741)

*Effects*: Equivalent to:for (; first != last; ++first)::new (*voidify*(*first)) remove_reference_t<iter_reference_t<I>>;return first;

[🔗](#lib:uninitialized_default_construct_n)

`template<class NoThrowForwardIterator, class Size>
  constexpr NoThrowForwardIterator
    uninitialized_default_construct_n(NoThrowForwardIterator first, Size n);
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L13759)

*Effects*: Equivalent to:for (; n > 0; (void)++first, --n)::new (*voidify*(*first))typename iterator_traits<NoThrowForwardIterator>::value_type;return first;

[🔗](#lib:uninitialized_default_construct_n_)

`namespace ranges {
  template<[nothrow-forward-iterator](special.mem.concepts#concept:nothrow-forward-iterator "26.11.2 Special memory concepts [special.mem.concepts]") I>
    requires [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")<iter_value_t<I>>
    constexpr I uninitialized_default_construct_n(I first, iter_difference_t<I> n);
}
`

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L13780)

*Effects*: Equivalent to:return uninitialized_default_construct(counted_iterator(first, n),
 default_sentinel).base();