[#BloombergLP-bslstl-SimplePool]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bslstl.adoc[bslstl]::SimplePool
:relfileprefix: ../../
:mrdocs:

Memory pool that allocates blocks of a fixed value type.

== Synopsis

Declared in `<bslstl_simplepool.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class VALUE,
    class ALLOCATOR>
class SimplePool
    : public SimplePool_Type<ALLOCATOR>::AllocatorType
----

== Description

This class provides methods for creating and deleting nodes using the appropriate allocator‐traits of the parameterized `ALLOCATOR`. This type is intended to be used as a private base‐class for a node‐based container, in order to take advantage of the empty‐base‐class optimization in the case where the base‐class has 0 size (as may the case if the parameterized `ALLOCATOR` is not a `bslma::Allocator`).

== Base Classes

[cols="1,4"]
|===
| Name| Description
| `SimplePool_Type<ALLOCATOR>::AllocatorType`
| 
|===

== Type Aliases

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bslstl/SimplePool/AllocatorTraits.adoc[`AllocatorTraits`] 
| Alias for the allocator traits for the parameterized `ALLOCATOR`.
| xref:BloombergLP/bslstl/SimplePool/AllocatorType.adoc[`AllocatorType`] 
| Alias for the allocator type for a `bsls::AlignmentUtil::MaxAlignedType`.
| xref:BloombergLP/bslstl/SimplePool/ValueType.adoc[`ValueType`] 
| Alias for the parameterized type `VALUE`.
| xref:BloombergLP/bslstl/SimplePool/size_type.adoc[`size_type`] 
| Unsigned integer type measuring pool size.
|===


== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bslstl/SimplePool/2constructor-01.adoc[`SimplePool`]         [.small]#[constructor]#
| Create a memory pool that adopts the allocations of `original`.
| xref:BloombergLP/bslstl/SimplePool/2constructor-0d.adoc[`SimplePool`]         [.small]#[constructor]#
| Create a memory pool that uses the specified `allocator`.
| xref:BloombergLP/bslstl/SimplePool/2destructor.adoc[`~SimplePool`] [.small]#[destructor]#
| Destroy this pool, releasing all associated memory back to the underlying allocator.
| xref:BloombergLP/bslstl/SimplePool/adopt.adoc[`adopt`] 
| Adopt all outstanding allocations from the specified `pool`.
| xref:BloombergLP/bslstl/SimplePool/allocate.adoc[`allocate`] 
| Return the address of a block of memory of at least the size of `VALUE`. Note that the memory is _not_ initialized.
| xref:BloombergLP/bslstl/SimplePool/allocator-01.adoc[`allocator`] 
| Return a modifiable reference to this pool's rebound allocator.
| xref:BloombergLP/bslstl/SimplePool/allocator-0d.adoc[`allocator`] 
| Return a non‐modifiable reference to this pool's rebound allocator.
| xref:BloombergLP/bslstl/SimplePool/deallocate.adoc[`deallocate`] 
| Relinquish the memory block at `address` back to this pool.
| xref:BloombergLP/bslstl/SimplePool/hasFreeBlocks.adoc[`hasFreeBlocks`] 
| Return `true` if this object holds free (currently unused) blocks, and `false` otherwise.
| xref:BloombergLP/bslstl/SimplePool/quickSwapExchangeAllocators.adoc[`quickSwapExchangeAllocators`] 
| Exchange this pool's memory blocks and allocator with those of `other`.
| xref:BloombergLP/bslstl/SimplePool/quickSwapRetainAllocators.adoc[`quickSwapRetainAllocators`] 
| Exchange this pool's memory blocks with those of `other`.
| xref:BloombergLP/bslstl/SimplePool/release.adoc[`release`] 
| Relinquish all memory currently allocated via this pool object.
| xref:BloombergLP/bslstl/SimplePool/reserve.adoc[`reserve`] 
| Reserve memory for at least the specified `numBlocks`.
| xref:BloombergLP/bslstl/SimplePool/swap.adoc[`swap`] 
| Exchange this pool's memory blocks with those of `other`.
|===



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