operator-(ranges::zip_view::sentinel)
|
template
<
bool OtherConst >
requires (
std::sized_sentinel_for
<
|
(1) | (since C++23) |
|
template
<
bool OtherConst >
requires (
std::sized_sentinel_for
<
|
(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>
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
DIST(x, y, i) of all i in range 0 ≤ i < sizeof...(Views)Example
#include <cassert> #include <deque> #include <list> #include <ranges> #include <vector> 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(); }