[#BloombergLP-bdlcc-TimeQueue-091]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlcc.adoc[bdlcc]::xref:BloombergLP/bdlcc/TimeQueue-09c.adoc[TimeQueue]<xref:bsl/function-0a.adoc[function<void()>]>
:relfileprefix: ../../
:mrdocs:

This parameterized class provides a public interface which is similar in structure and intent to `Queue<DATA>`, with the exception that each item stored in the `TimeQueue` has an associated time value. Items are retrieved or exchanged by proxy of a `TimeQueueItem<DATA>`, and are referred to by an opaque data type `TimeQueue::Handle` which serves to identify an individual element on the Time Queue. Idiomatic usage of `TimeQueue` includes the member function `popLE`, which finds all items on the queue whose `bsls::TimeInterval` are less than a specified value and transfers those items to a provided vector of items, and the member function `update`, which can update the time value for a specific `TimeQueueItem` without removing it from the queue.

== Synopsis

Declared in `<bdlcc_timequeue.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<>
class xref:BloombergLP/bdlcc/TimeQueue-09c.adoc[TimeQueue]<xref:bsl/function-0a.adoc[function<void()>]>;
----

== Types

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlcc/TimeQueue-091/Key.adoc[`Key`] 
| This type is a wrapper around a void pointer that will be supplied and used by clients to uniquely identify an item in the queue.
|===


== Type Aliases

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlcc/TimeQueue-091/Handle.adoc[`Handle`] 
| `Handle` defines an alias for uniquely identifying a valid node in the time queue. Handles are returned when nodes are added to the time queue, and must be supplied to the `update` and `remove` methods to identify existing nodes. When a node is removed, the handle value becomes invalid, though invalidated handle values are eventually reused. See the component‐level documentation for more details.
|===


== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlcc/TimeQueue-091/2constructor-0bc.adoc[`TimeQueue`]         [.small]#[constructor]#
| Constructors
| xref:BloombergLP/bdlcc/TimeQueue-091/2destructor.adoc[`~TimeQueue`] [.small]#[destructor]#
| Destroy this time queue.
| xref:BloombergLP/bdlcc/TimeQueue-091/add-0c.adoc[`add`] 
| `add` overloads
| xref:BloombergLP/bdlcc/TimeQueue-091/countLE.adoc[`countLE`] 
| Return the number of items in this queue that have a time value less than or equal to the specified `time`. Note that the value returned may be obsolete by the time it is received.
| xref:BloombergLP/bdlcc/TimeQueue-091/isRegisteredHandle-00.adoc[`isRegisteredHandle`] 
| `isRegisteredHandle` overloads
| xref:BloombergLP/bdlcc/TimeQueue-091/length.adoc[`length`] 
| Return number of items in this queue. Note that the value returned may be obsolete by the time it is received.
| xref:BloombergLP/bdlcc/TimeQueue-091/minTime.adoc[`minTime`] 
| Load into the specified `buffer`, the time value of the lowest time in this queue. Return 0 on success, and a non‐zero value if this queue is empty.
| xref:BloombergLP/bdlcc/TimeQueue-091/popFront.adoc[`popFront`] 
| Atomically remove the top item from this queue, and optionally load into the optionally specified `buffer` the time and associated data of the item removed. Optionally load into the optionally specified `newLength`, the number of items remaining in the queue. Optionally load into the optionally specified `newMinTime` the new lowest time in this queue. Return 0 on success, and a non‐zero value if there are no items in the queue. Note that if `DATA` follows the `bdema` allocator model, the allocator of the `buffer` is used to supply memory.
| xref:BloombergLP/bdlcc/TimeQueue-091/popLE-055.adoc[`popLE`] 
| `popLE` overloads
| xref:BloombergLP/bdlcc/TimeQueue-091/remove-06.adoc[`remove`] 
| `remove` overloads
| xref:BloombergLP/bdlcc/TimeQueue-091/removeAll.adoc[`removeAll`] 
| Remove all the items from this queue. Optionally specify a `removedItems` vector in which to load the removed items. The resultant items in the `buffer` are ordered by increasing time interval; items of equivalent time interval have arbitrary ordering. Note that the allocator of the `removedItems` vector is used to supply memory.
| xref:BloombergLP/bdlcc/TimeQueue-091/removeIf.adoc[`removeIf`] 
| Remove all the items from this queue for which `predicate` returns `true`. Optionally specify `newLength`, in which to load the number of items remaining in this queue. Optionally specify `newMinTime`, in which to load the lowest remaining time value in this queue. Optionally specify a vector of `removedItems` in which to load the removed items.
| xref:BloombergLP/bdlcc/TimeQueue-091/update-01.adoc[`update`] 
| `update` overloads
|===



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