operator==,!=,<,<=,>,>=,<=>(std::move_iterator)
From cppreference.com
< cpp | iterator | move iterator
| Defined in header <iterator>
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template< class Iter1, class Iter2 > bool operator==( const std::move_iterator<Iter1>& lhs, |
(1) | (constexpr since C++17) |
template< class Iter1, class Iter2 > bool operator!=( const std::move_iterator<Iter1>& lhs, |
(2) | (constexpr since C++17) (until C++20) |
template< class Iter1, class Iter2 > bool operator< ( const std::move_iterator<Iter1>& lhs, |
(3) | (constexpr since C++17) |
template< class Iter1, class Iter2 > bool operator<=( const std::move_iterator<Iter1>& lhs, |
(4) | (constexpr since C++17) |
template< class Iter1, class Iter2 > bool operator> ( const std::move_iterator<Iter1>& lhs, |
(5) | (constexpr since C++17) |
template< class Iter1, class Iter2 > bool operator>=( const std::move_iterator<Iter1>& lhs, |
(6) | (constexpr since C++17) |
| template< class Iter1, std::three_way_comparable_with<Iter1> Iter2 > constexpr std::compare_three_way_result_t<Iter1, Iter2> |
(7) | (since C++20) |
Compares the underlying iterators of lhs and rhs.
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1) This overload participates in overload resolution only if lhs.base() == rhs.base() is well-formed and convertible to bool.
3-6) These overloads participate in overload resolution only if lhs.base() < rhs.base() is well-formed and convertible to bool.
The |
(since C++20) |
Contents |
[edit] Parameters
| lhs, rhs | - | iterator adaptors to compare |
[edit] Return value
1) lhs.base() == rhs.base()
2) !(lhs == rhs)
3) lhs.base() < rhs.base()
4) !(rhs < lhs)
5) rhs < lhs
6) !(lhs < rhs)
7) lhs.base() <=> rhs.base()
[edit] Example
Run this code
#include <cassert> #include <iterator> int main() { int a[]{9, 8, 7, 6}; // │ └───── x, y // └──────── z // “x” and “y” are equal, but “x” is greater than “z” std::move_iterator<int*> x{std::end(a) - 1}, y{std::end(a) - 1}, z{std::end(a) - 2}; // two-way comparisons assert( x == y ); assert(!(x != y)); assert(!(x < y)); assert( x <= y ); assert(!(x == z)); assert( x != z ); assert(!(x < z)); assert(!(x <= z)); // three-way comparisons assert( x <=> y == 0 ); assert(!(x <=> y < 0)); assert(!(x <=> y > 0)); assert(!(x <=> z == 0)); assert(!(x <=> z < 0)); assert( x <=> z > 0 ); }
[edit] See also
| compares the underlying iterator and the underlying sentinel (function template) |
