NAME

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

Synopsis

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

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

std::experimental::ranges::less_equal::operator()

constexpr bool operator()(const T& x, const T& (1) (member only of primary
y) const; less_equal<T> template)
template< class T, class U >

requires StrictTotallyOrderedWith<T, U> ||
/* std::declval<T>() < std::declval<U>() (2) (member only of less_equal<void>
resolves to 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));.

Notes

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.

Example