C++ concepts: ForwardIterator
From cppreference.com
A ForwardIterator
is an Iterator
that can read data from the pointed-to element.
Unlike an InputIterator
, it guarantees validity when used in multipass algorithms.
[edit] Requirements
-
InputIterator
-
DefaultConstructible
-
a == b
implies++a == ++b
In addition to the above requirements, for a type It
to be an ForwardIterator
, an instance i
of It
must:
Expression | Return | Equivalent expression | Notes |
---|---|---|---|
++i | iterator | i=std::next(i); return i; | After this, copies of i are still valid
|
i++ | iterator | iterator ip=i; i=std::next(i); return ip; | |
*i++ | reference | value_type& temp=*i; ++i; return temp; |
A mutable ForwardIterator
is a ForwardIterator
that additionally satisfies the OutputIterator
requirements.
A value-initialized ForwardIterator behaves like the past-the-end iterator of some unspecified empty container: it compares equal to all value-initialized ForwardIterator s of the same type. |
(since C++14) |