[#BloombergLP-bdlcc-Queue-tryPopFront-039]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlcc.adoc[bdlcc]::xref:BloombergLP/bdlcc/Queue.adoc[Queue]::tryPopFront
:relfileprefix: ../../../
:mrdocs:

`tryPopFront` overloads

== Synopses

Declared in `<bdlcc_queue.h>`

Remove up to the specified `maxNumItems` from the front of this queue. Optionally specify a `buffer` into which the items removed from the queue are loaded. If `buffer` is non‐null, the removed items are appended to it as if by repeated application of `buffer‐>push_back(popFront())` while the queue is not empty and `maxNumItems` have not yet been removed. The behavior is undefined unless `maxNumItems >= 0`. This method never blocks.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
void
xref:BloombergLP/bdlcc/Queue/tryPopFront-05.adoc[tryPopFront](int maxNumItems);
----

[.small]#xref:BloombergLP/bdlcc/Queue/tryPopFront-05.adoc[_» more..._]#

If this queue is non‐empty, remove the first item, load that item into the specified `buffer`, and return 0 indicating success. If this queue is empty, return a non‐zero value with no effect on `buffer` or the state of this queue. This method never blocks.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
xref:BloombergLP/bdlcc/Queue/tryPopFront-09.adoc[tryPopFront](TYPE* buffer);
----

[.small]#xref:BloombergLP/bdlcc/Queue/tryPopFront-09.adoc[_» more..._]#

Same as the preceding overload, appending removed items to `buffer`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
void
xref:BloombergLP/bdlcc/Queue/tryPopFront-01.adoc[tryPopFront](
    int maxNumItems,
    xref:bsl/vector-00d.adoc[bsl::vector<TYPE>]* buffer);
----

[.small]#xref:BloombergLP/bdlcc/Queue/tryPopFront-01.adoc[_» more..._]#

Same as the preceding overload, appending removed items to `buffer`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
void
xref:BloombergLP/bdlcc/Queue/tryPopFront-031.adoc[tryPopFront](
    int maxNumItems,
    std::pmr::vector<TYPE>* buffer);
----

[.small]#xref:BloombergLP/bdlcc/Queue/tryPopFront-031.adoc[_» more..._]#

Same as the preceding overload, appending removed items to `buffer`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
void
xref:BloombergLP/bdlcc/Queue/tryPopFront-04.adoc[tryPopFront](
    int maxNumItems,
    std::vector<TYPE>* buffer);
----

[.small]#xref:BloombergLP/bdlcc/Queue/tryPopFront-04.adoc[_» more..._]#


[.small]#Created with https://www.mrdocs.com[MrDocs]#