[#BloombergLP-bslstl-Function_IsInvocableWithPrototype-00]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bslstl.adoc[bslstl]::xref:BloombergLP/bslstl/Function_IsInvocableWithPrototype-06.adoc[Function&lowbar;IsInvocableWithPrototype]&lt;RET(ARGS&period;&period;&period;), FUNC&gt;
:relfileprefix: ../../
:mrdocs:

This component&hyphen;private `struct` template provides a boolean metafunction that derives from `bsl&colon;&colon;true&lowbar;type` if a `bsl&colon;&colon;function` object having a prototype of `RET(ARGS&period;&period;&period;)` is constructible from an object of type `FUNC`, and derives from `bsl&colon;&colon;false&lowbar;type` otherwise&period; This metafunction is a wrapper around `bsl&colon;&colon;invoke&lowbar;result` that unwraps `FUNC` if it is a specialization of `bslalg&colon;&colon;NothrowMovableWrapper`&semi; and, if `bsl&colon;&colon;invoke&lowbar;result` provides a nested `type` typedef for `FUNC` and `RET` is non&hyphen;void, checks that the return type of the invoke operation on `FUNC` is convertible to `RET`&period;

== Synopsis

Declared in `&lt;bslstl&lowbar;function&period;h&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template&lt;
    class RET,
    class FUNC,
    class&period;&period;&period; ARGS&gt;
struct xref:BloombergLP/bslstl/Function_IsInvocableWithPrototype-06.adoc[Function&lowbar;IsInvocableWithPrototype]&lt;RET(ARGS&period;&period;&period;), FUNC&gt;
    : xref:BloombergLP/bslstl/Function_InvokerUtil/IsFuncInvocable.adoc[Function&lowbar;InvokerUtil::IsFuncInvocable&lt;RET(ARGS&period;&period;&period;), FUNC&gt;]
----

== Base Classes

[cols="1,4"]
|===
| Name| Description
| `xref:BloombergLP/bslstl/Function_InvokerUtil/IsFuncInvocable.adoc[Function&lowbar;InvokerUtil::IsFuncInvocable&lt;RET(ARGS&period;&period;&period;), FUNC&gt;]`
| This `struct` template implements a Boolean metafunction that publicly inherits from `bsl&colon;&colon;true&lowbar;type` if an object of the specified `FUNC` type is invocable under the specified `PROTOTYPE`, and publicly inherits from `bsl&colon;&colon;false&lowbar;type` otherwise&period; An object of `FUNC` type is invocable under the `PROTOTYPE` if it is Lvalue&hyphen;Callable with the arguments of the `PROTOTYPE` (as forwarded by the facilities of &apos;bslmf&lowbar;forwardingtype), and returns an object of type explicitly convertible to the return type of the `PROTOTYPE`&period; If the return type of the `PROTOTYPE` is `void`, then any type is considered explicitly convertible to the return type of the `PROTOTYPE`&period; This `struct` template requires `PROTOTYPE` to be an unqualified function type&period;
|===


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