[#BloombergLP-bslstl-Optional_Base-05-emplace-0f]
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Assign to this `Optional_Base` object the value of the (template parameter) `t_TYPE` created in place using the specified `args` and return a reference providing modifiable access to the underlying `t_TYPE` object. If this `Optional_Base` object already contains an object (`true == hasValue()`), that object is destroyed before the new object is created. The allocator specified at the construction of this `Optional_Base` object is used to supply memory to the value object. Attempts to explicitly specify via `args` another allocator to supply memory to the created (value) object are disallowed by the compiler. Note that if the constructor of `t_TYPE` throws an exception this object is left in a disengaged state.

== Synopsis

Declared in `<bslstl_optional.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<class... t_ARGS>
t_TYPE&
emplace(t_ARGS&&... args);
----


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