operator-(ranges::zip_view::sentinel)

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Ranges library

Range access
begin cbegin end cend	rbegin crbegin rend crend	size ssize data cdata	empty
Range conversions
to (C++23)
Range primitives
range_size_trange_difference_t range_value_t	range_reference_trange_const_reference_trange_rvalue_reference_t   (C++23)	iterator_tconst_iterator_tsentinel_t (C++23)
Dangling iterator handling
dangling	borrowed_iterator_t	borrowed_subrange_t
Range concepts
range borrowed_range    sized_range constant_range (C++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
Views
view_interface	subrange
Factories
empty_viewviews::empty iota_viewviews::iota	single_viewviews::single basic_istream_viewviews::istream	repeat_viewviews::repeat (C++23)(C++23)
Adaptors
ref_view views::all_tviews::all common_viewviews::common owning_view views::counted reverse_viewviews::reverse zip_viewviews::zip (C++23)(C++23) as_const_viewviews::as_const (C++23)(C++23) as_rvalue_viewviews::as_rvalue (C++23)(C++23)	take_viewviews::take take_while_viewviews::take_while drop_viewviews::drop drop_while_viewviews::drop_while zip_transform_viewviews::zip_transform (C++23)(C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23)   cartesian_product_viewviews::cartesian_product (C++23)(C++23)	elements_viewviews::elements keys_viewviews::keys values_viewviews::values transform_viewviews::transform adjacent_viewviews::adjacent (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) stride_viewviews::stride (C++23)(C++23)	filter_viewviews::filter join_viewviews::join split_viewviews::split lazy_split_viewviews::lazy_split join_with_viewviews::join_with (C++23)(C++23) chunk_viewviews::chunk (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23)
Range adaptor objects
Range adaptor closure objects
Helper items
copyable-box	simple-view

 

std::ranges::zip_view

Member functions

zip_view::zip_view (C++23)

zip_view::begin (C++23)

zip_view::end (C++23)

zip_view::size (C++23)

Deduction guides

Iterator

zip_view::iterator::iterator (C++23)

zip_view::iterator::operator* (C++23)

zip_view::iterator::operator[] (C++23)

zip_view::iterator::operator++ zip_view::iterator::operator++(int) zip_view::iterator::operator-- zip_view::iterator::operator--(int) zip_view::iterator::operator+= zip_view::iterator::operator-= (C++23)(C++23)(C++23)(C++23)(C++23)(C++23)

operator==(zip_view::iterator) operator<(zip_view::iterator) operator>(zip_view::iterator) operator<=(zip_view::iterator) operator>=(zip_view::iterator) operator<=>(zip_view::iterator) (C++23)(C++23)(C++23)(C++23)(C++23)(C++23)

operator+(zip_view::iterator) operator-(zip_view::iterator) (C++23)(C++23)

iter_move(zip_view::iterator) (C++23)

iter_swap(zip_view::iterator) (C++23)

Sentinel

zip_view::sentinel::sentinel (C++23)

operator==(zip_view::sentinel) (C++23)

operator-(zip_view::sentinel) (C++23)

 

template< bool OtherConst >   requires (std::sized_sentinel_for<               ranges::sentinel_t</*maybe-const*/<Const, Views>>,               ranges::iterator_t</*maybe-const*/<OtherConst, Views>>> && ...) friend constexpr   std::common_type_t<ranges::range_difference_t</*maybe-const*/<OtherConst, Views>>...>       operator-( const iterator<OtherConst>& x, const sentinel& y );	(1)	(since C++23)
template< bool OtherConst >   requires (std::sized_sentinel_for<               ranges::sentinel_t</*maybe-const*/<Const, Views>>,               ranges::iterator_t</*maybe-const*/<OtherConst, Views>>> && ...) friend constexpr   std::common_type_t<ranges::range_difference_t</*maybe-const*/<OtherConst, Views>>...>     operator-( const sentinel& y, const iterator<OtherConst>& x );	(2)	(since C++23)

Computes the minimal distance between the underlying tuple of iterators of x and the underlying tuple of sentinels of y.

These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when zip_view::sentinel<Const> is an associated class of the arguments.

Parameters

x	-	an iterator
y	-	a sentinel

Return value

Let current_ denote the underlying tuple of iterators of x, and end_ denote the underlying tuple of sentinels of y.

Let DIST(x, y, i) be a distance calculated by expression equivalent to std::get<i>(x.current_) - std::get<i>(y.end_) for some integer i.

1) the value with the smallest absolute value among DIST(x, y, i) of all i in range 0 ≤ i < sizeof...(Views)

2) -(x - y)

Example

Run this code

#include <cassert>
#include <ranges>
#include <vector>
#include <deque>
#include <list>
 
int main() {
    auto x = std::vector{1, 2, 3, 4};
    auto y = std::deque{'a', 'b', 'c'};
    auto z = {1.1, 2.2};
    auto w = std::list{1, 2, 3};
 
    auto p = std::views::zip(x, y, z);
    assert(p.begin() - p.end() == +2);
    assert(p.end() - p.begin() == -2);
 
    [[maybe_unused]]
    auto q = std::views::zip(x, y, w);
 
    // The following code fires a compile-time error because std::list::iterator
    // does not support operator- that is needed to calculate the distance:
    // auto e = q.begin() - q.end();
}