[func.wrap.copy.inv] # 22 General utilities library [[utilities]](./#utilities) ## 22.10 Function objects [[function.objects]](function.objects#func.wrap.copy.inv) ### 22.10.17 Polymorphic function wrappers [[func.wrap]](func.wrap#copy.inv) #### 22.10.17.5 Copyable wrapper [[func.wrap.copy]](func.wrap.copy#inv) #### 22.10.17.5.4 Invocation [func.wrap.copy.inv] [🔗](#lib:operator_bool,copyable_function) `explicit operator bool() const noexcept; ` [1](#1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L14858) *Returns*: true if *this has a target object, otherwise false[.](#1.sentence-1) [🔗](#lib:operator(),copyable_function) `R operator()(ArgTypes... args) cv ref noexcept(noex); ` [2](#2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L14869) *Preconditions*: *this has a target object[.](#2.sentence-1) [3](#3) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L14873) *Effects*: Equivalent to:return *INVOKE*(static_cast(f), std::forward(args)...); where f is an lvalue designating the target object of *this andF is the type of f[.](#3.sentence-1)