std::experimental::ranges::less_equal (3) - Linux Manuals

std::experimental::ranges::less_equal: std::experimental::ranges::less_equal


std::experimental::ranges::less_equal - std::experimental::ranges::less_equal


Defined in header <experimental/ranges/functional>
template< class T = void >
requires StrictTotallyOrdered<T> ||
Same<T, void> || (ranges TS)
/* < on two const T lvalues invokes a built-in operator comparing pointers */
struct less_equal;
template <> (ranges TS)
struct less_equal<void>;

Function object for performing comparisons. The primary template invokes operator< on const lvalues of type T with the argument order inverted and then negates the result. The specialization less_equal<void> deduces the parameter types of the function call operator from the arguments (but not the return type).
All specializations of less_equal are Semiregular.

Member types

Member type Definition
is_transparent (member only of less_equal<void> specialization) /* unspecified */

Member functions

           checks if the first argument is less than or equal to the second
operator() (public member function)


constexpr bool operator()(const T& x, const T& y) const; (1) (member only of primary less_equal<T> template)
template< class T, class U >
requires StrictTotallyOrderedWith<T, U> ||
/* std::declval<T>() < std::declval<U>() resolves to (2) (member only of less_equal<void> specialization)
a built-in operator comparing pointers */
constexpr bool operator()(T&& t, U&& u) const;

1) Compares x and y. Equivalent to return !ranges::less<>{}(y, x);
2) Compares t and u. Equivalent to return !ranges::less<>{}(std::forward<U>(u), std::forward<T>(t));.


Unlike std::less_equal, ranges::less_equal requires all six comparison operators <, <=, >, >=, == and != to be valid (via the StrictTotallyOrdered and StrictTotallyOrderedWith constraints) and is entirely defined in terms of ranges::less. However, the implementation is free to use operator<= directly, because those concepts require the results of the comparison operators to be consistent.


 This section is incomplete
 Reason: no example

See also

           function object implementing x <= y
less_equal (class template)