std::tuple_size<std:ranges::subrange>

 

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Ranges library

Range access begin cbegin   end cend rbegin crbegin   rend crend size ssize   data cdata reserve_hint (C++26)   empty

Range conversions std::from_range_t std::from_range (C++23)(C++23)     to (C++23)

Dangling iterator handling dangling borrowed_iterator_t borrowed_subrange_t

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range_size_trange_difference_trange_value_t elements_of (C++23)	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_reference_trange_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)

Range concepts
range borrowed_range    common_range	sized_range viewable_range    view	input_range output_range forward_range	bidirectional_range    random_access_range contiguous_range	approximately_sized_range (C++26) constant_range (C++23)

Views
view_interface	subrange

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empty_viewviews::empty	single_viewviews::single	basic_istream_viewviews::istream	iota_viewviews::iota	repeat_viewviews::repeat (C++23)(C++23)

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views::all_tviews::all as_rvalue_viewviews::as_rvalue (C++23)(C++23)   filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while common_viewviews::common views::counted to_input_viewviews::to_input (C++26)(C++26)	ref_view drop_viewviews::drop drop_while_viewviews::drop_while lazy_split_viewviews::lazy_split split_viewviews::split join_viewviews::join join_with_viewviews::join_with (C++23)(C++23)   concat_viewviews::concat (C++26)(C++26) cache_latest_viewviews::cache_latest (C++26)(C++26)	owning_view reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)

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Range adaptor objects

Helper items
copyable-box movable-box (until C++23)  (C++23)	simple-view non-propagating-cache

 

std::ranges::subrange

Member functions

subrange::subrange

subrange::operator PairLike

Observers

subrange::begin

subrange::end

subrange::empty

subrange::size

Iterator operations

subrange::advance

subrange::next

subrange::prev

Deduction guides

Non-member functions

get(std::ranges::subrange)

Helper types

subrange_kind

tuple_size<std::ranges::subrange>

tuple_element<std::ranges::subrange>

 

Defined in header <ranges>
template<class I, class S, ranges::subrange_kind K > struct tuple_size<ranges::subrange<I, S, K>>     :std::integral_constant<std::size_t, 2>{};		(since C++20)

The partial specialization of std::tuple_size for std::ranges::subrange provides a compile-time way to obtain the number of components of a subrange, which is always 2, using tuple-like syntax. It is provided for structured binding support.

Inherited from std::integral_constant

Member constants

value [static]

the constant value 2 (public static member constant)

Member functions

operator std::size_t	converts the object to std::size_t, returns value (public member function)
operator() (C++14)	returns value (public member function)

Member types

Type	Definition
value_type	std::size_t
type	std::integral_constant<std::size_t, value>

Example

Run this code

#include <array>#include <iostream>#include <iterator>#include <ranges>   int main(){ static_assert(2==std::tuple_size_v<std::ranges::subrange<int*, int*>>);   using array5 =std::array<int, 5>;   static_assert(2==std::tuple_size<std::ranges::subrange< array5::const_iterator, array5::const_iterator>>{});   constexpr array5 a{1, 2, 3, 4, 5};   std::ranges::subrange sub_a1{a};   for(std::cout<<"sub_a1: { ";int e : sub_a1)std::cout<< e <<' ';std::cout<<"}\n";   std::ranges::subrange sub_a2{std::next(cbegin(a)), std::prev(cend(a))};   constauto[first, last]= sub_a2;std::cout<<"sub_a2 size = "<<std::distance(first, last)<<'\n';   for(std::cout<<"sub_a2: { ";int e : sub_a2)std::cout<< e <<' ';std::cout<<"}\n";}

Output:

sub_a1: { 1 2 3 4 5 } sub_a2 size = 3 sub_a2: { 2 3 4 }

See also

Structured binding(C++17)	binds the specified names to sub-objects or tuple elements of the initializer
tuple_size (C++11)	obtains the number of elements of a tuple-like type (class template)
std::tuple_size<std::tuple> (C++11)	obtains the size of a tuple (class template specialization)
std::tuple_size<std::pair> (C++11)	obtains the size of a pair (class template specialization)
std::tuple_size<std::array> (C++11)	obtains the size of an array (class template specialization)
std::tuple_element<std::ranges::subrange> (C++20)	obtains the type of the iterator or the sentinel of a std::ranges::subrange (class template specialization)