Outline
Purpose
Provide primitive algorithms that operate on deques.
Classes
- See also
- bslma_constructionutil, bslalg_arrayprimitives
Description
This component provides utilities to initialize, destroy, move, and otherwise perform various primitive manipulations on deques with a uniform interface, but selecting a different implementation according to the various traits possessed by the underlying type, and selecting a simpler implementation when there is only one element per deque block. See the bslalg_dequeimputil and bslalg_dequeiterator components for a definition and visual depiction of the internal organization of a deque, and of the iterator type used to refer to elements in the deque.
The primitives provided by this component are exceptionally useful for implementing generic block-based components such as deques. A short synopsis is provided below describing the observable behavior and mentioning the relevant traits. See the full function-level contract for detailed description, including exception-safety guarantees. In the description below, Ar stands for bslalg::ArrayPrimitives. Note that some algorithms are explained in terms of previous algorithms.
Algorithm Short description of observable behavior
---------------------------- ---------------------------------------------
destruct Destroy each element in the target range.
erase 'destruct' for each element in the target
range, or 'no-op' if bitwise copyable, then
shift the remaining elements from either the
front or the back to fill hole.
uninitializedFillNBack 'Ar::uninitializedFillN' for each block at
the end of the deque
uninitializedFillNFront 'Ar::uninitializedFillN' for each block at
the front of the deque.
valueInititalizeN 'Ar::defaultConstruct' for each block at the
end of the deque.
insertAndMoveToBack Copy construct each element in the target
range, or 'std::memmove' if type is bitwise
moveable, to the back of the deque to create
a hole, followed by copy construct of target
value or range to fill the hole.
insertAndMoveToFront Copy construct each element in the target
range, or 'std::memmove' if type is bitwise
moveable, to the front of the deque to create
a hole, followed by copy construct or
'std::memmove' of target value or range to
fill the hole.
moveInsertAndMoveToBack Move-construct or move-assign each element in
the target range (or 'std::memmove' if type
is bitwise moveable) to the back of the
deque to create a 1-slot hole, followed by
move-assign of the movable source value to
fill the hole.
moveInsertAndMoveToFront Move-construct or move-assign each element in
the target range (or 'std::memmove' if type
is bitwise moveable) to the front of the
deque to create a 1-slot hole, followed by
move-assign of the movable source value to
fill the hole.
emplaceAndMoveToBack Move-construct or move-assign each element in
the target range (or 'std::memmove' if type
is bitwise moveable) to the back of the
deque to create a 1-slot hole, followed by
in-place construction of the source value to
fill the hole.
emplaceAndMoveToFront Move-construct or move-assign each element in
the target range (or 'std::memmove' if type
is bitwise moveable) to the front of the
deque to create a 1-slot hole, followed by
in-place construction of the source value to
fill the hole.
The traits under consideration directly or indirectly by this component are:
Trait English description
----- -------------------
copyable trait", or
"TYPE is bitwise copyable"
moveable trait", or
"TYPE is bitwise moveable"
Definition bslmf_isbitwisecopyable.h:298
Definition bslmf_isbitwisemoveable.h:718
Aliasing
There are some aliasing concerns in this component, due to the presence of the reference const VALUE_TYPE& value argument, which may belong to a range that will be modified during the course of the operation. All such aliasing concerns are taken care of properly. Other aliasing concerns due to the copying of a range [first .. last) are not taken care of, since their intended use is for range assignments and insertions in standard containers, for which the standard explicitly says that first and last shall not be iterators into the container.
Usage
This component is for use by the bslstl package. Other clients should use the STL deque (in header <deque>).
◆ bslalg_DequePrimitives
1.9.8