25 Iterators library [iterators]

25.3 Iterator requirements [iterator.requirements]

25.3.5 C++17 iterator requirements [iterator.cpp17]

25.3.5.2 Cpp17Iterator [iterator.iterators]

The Cpp17Iterator requirements form the basis of the iterator taxonomy; every iterator meets the Cpp17Iterator requirements.
This set of requirements specifies operations for dereferencing and incrementing an iterator.
Most algorithms will require additional operations to read ([input.iterators]) or write ([output.iterators]) values, or to provide a richer set of iterator movements ([forward.iterators], [bidirectional.iterators], [random.access.iterators]).
A type X meets the Cpp17Iterator requirements if
Table 89: Cpp17Iterator requirements [tab:iterator]
Expression
Return type
Operational
Assertion/note
semantics
pre-/post-condition
*r
unspecified
Preconditions: r is dereferenceable.
++r
X&