is_bidirectional_iterator

Header

#include <tick/traits/is_bidirectional_iterator.h>

Description

A bidirectional iterator is a forward iterator that can be moved in both directions (i.e. incremented and decremented).

Requirements

The type It satisfies is_bidirectional_iterator if

• The type It satisfies is_forward_iterator

And, given

• a and b, iterators of type It
• reference, the type denoted by std::iterator_traits<It>::reference

The following expressions must be valid and have their specified effects

Expression	Return	Equivalent expression
--a	It&
a--	convertible to It&	It temp = a; --a; return temp;
*a--	reference

Synopsis

TICK_TRAIT(is_bidirectional_iterator, is_forward_iterator<_>)
{
    template<class I>
    auto require(I&& i) -> valid<
        decltype(returns<typename std::add_lvalue_reference<I>::type>(--i)),
        decltype(returns<I>(i--)),
        decltype(returns<typename iterator_traits<I>::reference>(*i--))
    >;
};