# std::equal_to, not_equal_to, less, greater, less_equal, greater_equal(std::experimental::propagate_const)

From cppreference.com
< cpp‎ | experimental‎ | propagate const

Defined in header `<experimental/propagate_const>` |  |
template<class T> struct equal_to<std::experimental::propagate_const<T>>; |  | (library fundamentals TS v2)
template<class T> struct not_equal_to<std::experimental::propagate_const<T>>; |  | (library fundamentals TS v2)
template<class T> struct less<std::experimental::propagate_const<T>>; |  | (library fundamentals TS v2)
template<class T> struct greater<std::experimental::propagate_const<T>>; |  | (library fundamentals TS v2)
template<class T> struct less_equal<std::experimental::propagate_const<T>>; |  | (library fundamentals TS v2)
template<class T> struct greater_equal<std::experimental::propagate_const<T>>; |  | (library fundamentals TS v2)

The standard comparison function objects are partially specialized for std::experimental::propagate_const<T>.

Let p.t_ denote the pointer-like object wrapped by a std::experimental::propagate_const<T> p, then given objects `p` and `q` of type std::experimental::propagate_const<T>, the following shall hold:

- std::equal_to<std::experimental::propagate_const<T>>()(p, q) == std::equal_to<T>()(p.t_, q.t_)
- std::not_equal_to<std::experimental::propagate_const<T>>()(p, q) == std::not_equal_to<T>()(p.t_, q.t_)
- std::less<std::experimental::propagate_const<T>>()(p, q) == std::less<T>()(p.t_, q.t_)
- std::greater<std::experimental::propagate_const<T>>()(p, q) == std::greater<T>()(p.t_, q.t_)
- std::less_equal<std::experimental::propagate_const<T>>()(p, q) == std::less_equal<T>()(p.t_, q.t_)
- std::greater_equal<std::experimental::propagate_const<T>>()(p, q) == std::greater_equal<T>()(p.t_, q.t_)

### Notes

These specializations ensure that when `T` is a pointer type, specializations of these class templates for std::experimental::propagate_const<T> yield a total order, even if the corresponding built-in operators do not.

### Example

| This section is incomplete Reason: no example

### See also

equal_to | function object implementing x == y (class template)
not_equal_to | function object implementing x != y (class template)
less | function object implementing x < y (class template)
greater | function object implementing x > y (class template)
less_equal | function object implementing x <= y (class template)
greater_equal | function object implementing x >= y (class template)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/experimental/propagate_const/cmp_func&oldid=98259"