Section
std::copyable_function
Class template std::copyable_function is a general-purpose polymorphic function wrapper. std::copyable_function objects can store and invoke any CopyConstructible Callable target — functions, lambda expressions, bind expressions, or other function objects, as well as pointers to member functions and pointers to member objects.
# Declarations
template< class... >
class copyable_function; // not defined
(since C++26)
template< class R, class... Args >
class copyable_function<R(Args...)>;
template< class R, class... Args >
class copyable_function<R(Args...) noexcept>;
template< class R, class... Args >
class copyable_function<R(Args...) &>;
template< class R, class... Args >
class copyable_function<R(Args...) & noexcept>;
template< class R, class... Args >
class copyable_function<R(Args...) &&>;
template< class R, class... Args >
class copyable_function<R(Args...) && noexcept>;
template< class R, class... Args >
class copyable_function<R(Args...) const>;
template< class R, class... Args >
class copyable_function<R(Args...) const noexcept>;
template< class R, class... Args >
class copyable_function<R(Args...) const &>;
template< class R, class... Args >
class copyable_function<R(Args...) const & noexcept>;
template< class R, class... Args >
class copyable_function<R(Args...) const &&>;
template< class R, class... Args >
class copyable_function<R(Args...) const && noexcept>;
(since C++26)
# Notes
Implementations may store a callable object of small size within the std::copyable_function object. Such small object optimization is effectively required for function pointers and std::reference_wrapper specializations, and can only be applied to types T for which std::is_nothrow_move_constructible_v
# Example
This section is incompleteReason: no example