A Forward Iterator traverses a Sequence allowing movement in only one direction through it's elements, one element at a time.
Notation
i
, j
Forward Iterators
I
, J
Forward Iterator types
M
An MPL integral constant
N
An integral constant
A type models Forward Iterator if, in addition to being CopyConstructable, the following expressions are valid:
Expression 
Return type 
Runtime Complexity 


Constant 


Convertible to bool 
Constant 

Convertible to bool 
Constant 

Constant 


Constant 



Constant 


Constant 


Constant 
Expression 
Compile Time Complexity 


Amortized constant time 

Amortized constant time 

Linear 

Linear 

Linear 

Amortized constant time 

Amortized constant time 
Expression 
Semantics 


An iterator to the element following 

Iterator equality comparison 

Iterator inequality comparison 

An iterator n elements after 

Equivalent to 

The number of elements between 

The element at position 

Equivalent to 
The following invariants always hold:
std::pair
iterator
boost::array
iterator
vector
iterator
cons
iterator
list
iterator
set
iterator
map
iterator
single_view
iterator
filter_view
iterator
iterator_range
iterator
joint_view
iterator
transform_view
iterator
reverse_view
iterator