iox::cxx::function_ref< ReturnType(ArgTypes...)> Class Template Reference

cxx::function_ref is a non-owning reference to a callable. More...

#include <iceoryx_hoofs/cxx/function_ref.hpp>

Public Member Functions
	function_ref () noexcept
	Creates an empty function_ref in an invalid state.
	function_ref (const function_ref &) noexcept=default
function_ref &	operator= (const function_ref &) noexcept=default
template<typename CallableType, typename = std::enable_if_t<!is_function_pointer<CallableType>::value && !has_same_decayed_type<CallableType, function_ref>::value && is_invocable<CallableType, ArgTypes...>::value>>
	function_ref (CallableType &&callable) noexcept
	Creates a function_ref with a callable whose lifetime has to be longer than function_ref.
	function_ref (ReturnType(*function)(ArgTypes...)) noexcept
	Creates a function_ref from a function pointer.
	function_ref (function_ref &&rhs) noexcept
function_ref &	operator= (function_ref &&rhs) noexcept
ReturnType	operator() (ArgTypes... args) const noexcept
	Calls the provided callable.
	operator bool () const noexcept
	Checks whether a valid target is contained.
void	swap (function_ref &rhs) noexcept
	Swaps the contents of two function_ref's.

Detailed Description

template<class ReturnType, class... ArgTypes>
class iox::cxx::function_ref< ReturnType(ArgTypes...)>

cxx::function_ref is a non-owning reference to a callable.

   It has these features:
    * No heap usage
    * No exceptions
    * Stateful lambda support
    * C++11/14 support

Attention

Invoking an empty function_ref can lead to a program termination!

// Usage as function parameter
void fuu(cxx::function_ref<void()> callback)
{
    callback();
}
// Call the lambda
fuu([]{ doSomething(); });
 
// Usage with l-values
// Pitfall: Ensure that lifetime of callable suits the point in time of calling callback()
auto callable = [&]{ doSomething(); };
cxx::function_ref<void()> callback(callable);
// Call the callback
callback();

Constructor & Destructor Documentation

function_ref() [1/3]

template<class ReturnType, class... ArgTypes>

iox::cxx::function_ref< ReturnType(ArgTypes...)>::function_ref ( )

noexcept

Creates an empty function_ref in an invalid state.

Note

Handle with care, program will terminate when calling an invalid function_ref

function_ref() [2/3]

template<class ReturnType, class... ArgTypes>

template<typename CallableType, typename = std::enable_if_t<!is_function_pointer<CallableType>::value && !has_same_decayed_type<CallableType, function_ref>::value && is_invocable<CallableType, ArgTypes...>::value>>

iox::cxx::function_ref< ReturnType(ArgTypes...)>::function_ref ( CallableType && callable )

noexcept

Creates a function_ref with a callable whose lifetime has to be longer than function_ref.

Parameters

[in]

callable

that is not a function_ref

function_ref() [3/3]

template<class ReturnType, class... ArgTypes>

iox::cxx::function_ref< ReturnType(ArgTypes...)>::function_ref ( ReturnType(* function )(ArgTypes...) )

noexcept

Creates a function_ref from a function pointer.

Parameters

[in]

function

function pointer to function we want to reference

Note

This overload is needed, as the general implementation will not work properly for function pointers. This ctor is not needed anymore once we can use user-defined-deduction guides (C++17)

Member Function Documentation

operator bool()

template<class ReturnType, class... ArgTypes>

iox::cxx::function_ref< ReturnType(ArgTypes...)>::operator bool ( ) const

explicitnoexcept

Checks whether a valid target is contained.

Returns

True if valid target is contained, otherwise false

operator()()

template<class ReturnType, class... ArgTypes>

ReturnType iox::cxx::function_ref< ReturnType(ArgTypes...)>::operator() ( ArgTypes... args ) const

noexcept

Calls the provided callable.

Parameters

[in]

Arguments

are forwarded to the underlying function pointer

Returns

Returns the data type of the underlying function pointer

Attention

Invoking an empty function_ref can lead to a program termination!

swap()

template<class ReturnType, class... ArgTypes>

void iox::cxx::function_ref< ReturnType(ArgTypes...)>::swap ( function_ref< ReturnType(ArgTypes...)> & rhs )

noexcept

Swaps the contents of two function_ref's.

Parameters

[in]

Reference

to another function_ref

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The documentation for this class was generated from the following file:

• iceoryx_hoofs/cxx/function_ref.hpp