is_input_iterator

Header

#include <tick/traits/is_input_iterator.h>

Description

An input iterator is an iterator that can read from the pointed-to element. Input iterators only guarantee validity for single pass algorithms: once an inputIterator i has been incremented, all copies of its previous value may be invalidated.

Requirements

The type It satisfies InputIterator if

• The type It satisfies is_iterator
• The type It satisfies is_equality_comparable

And, given

• i and j, values of type It or const It
• reference, the type denoted by std::iterator_traits<It>::reference
• value_type, the type denoted by std::iterator_traits<It>::value_type

The following expressions must be valid and have their specified effects

Expression	Return	Equivalent expression	Notes
i != j	contextually convertible to bool	!(i == j)	Precondition: (i, j) is in the domain of ==.
*i	reference, convertible to value_type	If i == j and (i, j) is in the domain of == then this is equivalent to *j.	Precondition: i is dereferenceable. The expression (void)*i, *i is equivalent to *i.
i->m		(*i).m	Precondition: i is dereferenceable.
++i	It&		Precondition: i is dereferenceable. Postcondition: i is dereferenceable or i is past-the-end. Postcondition: Any copies of the previous value of i are no longer required to be either dereferenceable or to be in the domain of ==.
(void)i++		(void)++i
*i++	convertible to value_type	value_type x = *i; ++i; return x;

Synopsis

TICK_TRAIT(is_input_iterator, 
    is_iterator<_>, 
    is_equality_comparable<_>
)
{
    template<class I>
    auto require(I&& i) -> valid<
        decltype(returns<typename iterator_traits<I>::value_type>(*i)),
        decltype(returns<typename iterator_traits<I>::value_type>(*i++))
    >;
};