std::experimental::ranges::less_equal - cppreference.com (original) (raw)
| Defined in header <experimental/ranges/functional> | |||
|---|---|---|---|
| template< class T = void > requires StrictTotallyOrdered<T> | | Same<T, void> | /* < on two const T lvalues invokes a built-in operator comparing pointers */ struct less_equal; | |
| template<> struct less_equal<void>; | (ranges TS) |
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.
Contents
[edit] Member types
| Member type | Definition |
|---|---|
| is_transparent (member only of less_equal specialization) | /* unspecified */ |
[edit] Member functions
| | 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& y) const; | (1) | (member only of primary less_equal template) |
|---|---|---|
| template< class T, class U > requires StrictTotallyOrderedWith<T, U> | | /* std::declval() < std::declval() resolves to a built-in operator comparing pointers */ constexpr bool operator()(T&& t, U&& u) const; | (2) |
- Compares
xandy. Equivalent to return<>{}(y, x);.
[edit] 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.