Description
A Bidirectional Sequence is a Forward Sequence whose iterators model Bidirectional Iterator.
Refinement of
Notation
- s
A Forward Sequence
- S
A Forward Sequence type
- o
An arbitrary object
- e
A Sequence element
Valid Expressions
In addition to the requirements defined in Forward Sequence, for any Bidirectional Sequence the following must be met:
|
Expression |
Return type |
Type Requirements |
Runtime Complexity |
|---|---|---|---|
|
begin(s) |
|
Constant |
|
|
end(s) |
|
Constant |
|
|
back(s) |
Any type |
|
Constant |
|
back(s) = o |
Any type |
s is mutable and e = o, where e is the first element in the sequence, is a valid expression. |
Constant |
Result Type Expressions
|
Expression |
Compile Time Complexity |
|---|---|
|
result_of::begin<S>::type |
Amortized constant time |
|
result_of::end<S>::type |
Amortized constant time |
|
result_of::back<S>::type |
Amortized constant time |
Expression Semantics
The semantics of an expression are defined only where they differ from, or are not defined in Forward Sequence.
Models
- std::pair
- boost::array
- vector
- reverse_view
- iterator_range (where adapted sequence is a Bidirectional Sequence)
- transform_view (where adapted sequence is a Bidirectional Sequence)
- zip_view (where adapted sequences are models Bidirectional Sequence)