Copies the elements in the range, defined by [ first , last ) , to another range beginning at result .

The function-like entities described on this page are niebloids , that is:

• Explicit template argument lists cannot be specified when calling any of them.
• None of them are visible to argument-dependent lookup .
• When any of them are found by normal unqualified lookup as the name to the left of the function-call operator, argument-dependent lookup is inhibited.

  In practice, they may be implemented as function objects, or with special compiler extensions.

  Contents 1 Parameters 2 Return value 3 Complexity 4 Notes 5 Possible implementation 6 Example 7 See also [ edit ] Parameters [ edit ] Return value A ranges::in_out_result containing an input iterator equal to last and an output iterator past the last element copied. [ edit ] Complexity 1-2) Exactly last - first assignments. 3-4) Exactly last - first applications of the predicate and projection, between ​ 0 ​ and last - first assignments (assignment for every element for which predicate returns true , dependent on predicate and input data). [ edit ] Notes In practice, implementations of ranges::copy avoid multiple assignments and use bulk copy functions such as std::memmove if the value type is TriviallyCopyable and the iterator types satisfy contiguous_iterator . When copying overlapping ranges, ranges::copy is appropriate when copying to the left (beginning of the destination range is outside the source range) while ranges::copy_backward is appropriate when copying to the right (end of the destination range is outside the source range). [ edit ] Possible implementation struct copy_fn template<std::input_iterator I, std::sentinel_for<I> S, std::weakly_incrementable O> requires std::indirectly_copyable<I, O> constexpr ranges::copy_result<I, O> operator()(I first, S last, O result) const for (; first != last; ++first, (void)++result) *result = *first; return {std::move(first), std::move(result)}; template<ranges::input_range R, std::weakly_incrementable O> requires std::indirectly_copyable<ranges::iterator_t<R>, O> constexpr ranges::copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result) const return (*this)(ranges::begin(r), ranges::end(r), std::move(result)); inline constexpr copy_fn copy;	copy_if struct copy_if_fn template<std::input_iterator I, std::sentinel_for<I> S, std::weakly_incrementable O, class Proj = std::identity, std::indirect_unary_predicate<std::projected<I, Proj>> Pred> requires std::indirectly_copyable<I, O> constexpr ranges::copy_if_result<I, O> operator()(I first, S last, O result, Pred pred, Proj proj = {}) const for (; first != last; ++first) if (std::invoke(pred, std::invoke(proj, *first))) *result = *first; ++result; return {std::move(first), std::move(result)}; template<ranges::input_range R, std::weakly_incrementable O, class Proj = std::identity, std::indirect_unary_predicate< std::projected<ranges::iterator_t<R>, Proj>> Pred> requires std::indirectly_copyable<ranges::iterator_t<R>, O> constexpr ranges::copy_if_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, Pred pred, Proj proj = {}) const return (*this)(ranges::begin(r), ranges::end(r), std::move(result), std::ref(pred), std::ref(proj)); inline constexpr copy_if_fn copy_if; [ edit ] Example The following code uses ranges::copy to both copy the contents of one std::vector to another and to display the resulting std::vector : Run this code #include <algorithm> #include <iostream> #include <iterator> #include <numeric> #include <vector> int main() std::vector<int> source(10); std::iota(source.begin(), source.end(), 0); std::vector<int> destination; std::ranges::copy(source.begin(), source.end(), std::back_inserter(destination)); // or, alternatively, // std::vector<int> destination(source.size()); // std::ranges::copy(source.begin(), source.end(), destination.begin()); // either way is equivalent to // std::vector<int> destination = source; std::cout << "destination contains: "; std::ranges::copy(destination, std::ostream_iterator<int>(std::cout, " ")); std::cout << '\n'; std::cout << "odd numbers in destination are: "; std::ranges::copy_if(destination, std::ostream_iterator<int>(std::cout, " "), [](int x) { return (x % 2) == 1; }); std::cout << '\n'; Output: destination contains: 0 1 2 3 4 5 6 7 8 9 odd numbers in destination are: 1 3 5 7 9 [edit] See also	ranges::copy_backward (C++20)	copies a range of elements in backwards order (niebloid) [edit]	ranges::reverse_copy (C++20)	creates a copy of a range that is reversed (niebloid) [edit]	ranges::copy_n (C++20)	copies a number of elements to a new location (niebloid) [edit]	ranges::fill (C++20)	assigns a range of elements a certain value (niebloid) [edit]	ranges::remove_copy ranges::remove_copy_if (C++20) (C++20)	copies a range of elements omitting those that satisfy specific criteria (niebloid) [edit]	copy copy_if (C++11)	copies a range of elements to a new location (function template) [edit] Toolbox What links here Related changes Upload file Special pages Printable version Permanent link Page information In other languages Deutsch Español Français 日本語 Русский 中文 This page was last modified on 17 April 2023, at 13:33. This page has been accessed 49,130 times. Privacy policy About cppreference.com Disclaimers