std::counted_iterator<I>::count
From cppreference.com
< cpp | iterator | counted iterator
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Iterator library
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)(C++20)(C++23)(C++20)(C++20)
(deprecated in C++17)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++14)
(C++11)
(C++11)
(C++20)(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++23)
(C++23)
(C++23)
(C++23)
(C++23)
(C++11)(C++14)
(C++14)(C++14)
std::counted_iterator
counted_iterator::count
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
constexpr std::iter_difference_t <I> count() const noexcept;
(since C++20)
Returns the underlying length that is the distance to the end.
Contents
[edit] Parameters
(none)
[edit] Return value
The underlying length.
[edit] Example
Run this code
#include <cassert> #include <iostream> #include <iterator> int main() { constexpr static auto il = {1, 2, 3, 4, 5}; constexpr std::counted_iterator i1{il.begin() + 1, 3}; static_assert(i1.count() == 3); auto i2{i1}; for (; std::default_sentinel != i2; ++i2) std::cout << "*i2: " << *i2 << ", count(): " << i2.count() << '\n'; assert (i2.count() == 0); }
Output:
*i2: 2, count(): 3 *i2: 3, count(): 2 *i2: 4, count(): 1