A general-purpose static-polymorphic function wrapper via jau::function<R(A...)>. More...

Namespaces
namespace	jau::func

Classes
class	jau::func::capref_target_t< R, I, A >
	func::capref_target_t implementation for functions using a reference to a captured value, identifiable as func::target_type::capref via jau::function<R(A...)>::type(). More...

class	jau::func::capval_target_t< R, I, A >
	func::capval_target_t implementation for functions using a copy of a captured value, identifiable as func::target_type::capval via jau::function<R(A...)>::type(). More...

class	jau::func::delegate_t< R, A >
	Delegated target function object, providing a fast path target function invocation. More...

class	jau::func::free_target_t< R, A >
	func::free_target_t implementation for free functions, identifiable as func::target_type::free via jau::function<R(A...)>::type(). More...

class	jau::function< Signature >
	Class template jau::function is a general-purpose static-polymorphic function wrapper. More...

class	jau::function< R(A...)>
	Class template jau::function is a general-purpose static-polymorphic function wrapper. More...

class	jau::func::lambda_target_t< R, L, A >
	func::lambda_target_t implementation for lambda closures, identifiable as func::target_type::lambda via jau::function<R(A...)>::type(). More...

class	jau::func::member_target_t< R, C0, C1, A >
	func::member_target_t implementation for class member functions, identifiable as func::target_type::member via jau::function<R(A...)>::type(). More...

class	jau::func::null_target_t< R, A >
	func::null_target_t implementation for no function. More...

class	jau::func::std_target_t< R, A >
	func::std_target_t implementation for std::function instances, identifiable as func::target_type::std via jau::function<R(A...)>::type(). More...

class	jau::func::target_t< R, A >
	func::target_t pure-virtual interface for jau::function. More...

class	jau::func::ylambda_target_t< R, L, A >
	func::ylambda_target_t is a Y combinator and deducing this implementation for lambda closures usable for recursive algorithms. More...

Enumerations
enum class	jau::func::target_type : uint32_t { jau::func::target_type::null = 0 , jau::func::target_type::member = 1 , jau::func::target_type::free = 2 , jau::func::target_type::lambda = 3 , jau::func::target_type::ylambda = 4 , jau::func::target_type::capval = 5 , jau::func::target_type::capref = 6 , jau::func::target_type::std = 7 , jau::func::target_type::null = 0 , jau::func::target_type::member = 1 , jau::func::target_type::free = 2 , jau::func::target_type::lambda = 3 , jau::func::target_type::capval = 4 , jau::func::target_type::capref = 5 , jau::func::target_type::std = 6 }
	func::target_type identifier for the target function delegate_t<R, A...> object, exposed by jau::function<R(A...)>::type(). More...

enum class	jau::func::target_type : uint32_t { jau::func::target_type::null = 0 , jau::func::target_type::member = 1 , jau::func::target_type::free = 2 , jau::func::target_type::lambda = 3 , jau::func::target_type::ylambda = 4 , jau::func::target_type::capval = 5 , jau::func::target_type::capref = 6 , jau::func::target_type::std = 7 , jau::func::target_type::null = 0 , jau::func::target_type::member = 1 , jau::func::target_type::free = 2 , jau::func::target_type::lambda = 3 , jau::func::target_type::capval = 4 , jau::func::target_type::capref = 5 , jau::func::target_type::std = 6 }
	func::target_type identifier for specializations of func::target_t used by jau::function<R(A...)>::type(). More...

Functions
template<typename R , typename I , typename... A>
jau::function< R(A...)>	jau::bind_capref (I data_ptr, R(func)(I *, A...)) noexcept
	Bind given data by passing the captured reference (pointer) to the value and non-void function to an anonymous function using func::capref_target_t. More...

template<typename I , typename... A>
jau::function< void(A...)>	jau::bind_capref (I data_ptr, void(func)(I *, A...)) noexcept
	Bind given data by passing the captured reference (pointer) to the value and void function to an anonymous function using func::capref_target_t. More...

template<typename R , typename I , typename... A>
jau::function< R(A...)>	jau::bind_capval (const I &data, R(*func)(I &, A...)) noexcept
	Bind given data by copying the captured value and the given non-void function to an anonymous function using func::capval_target_t. More...

template<typename I , typename... A>
jau::function< void(A...)>	jau::bind_capval (const I &data, void(*func)(I &, A...)) noexcept
	Bind given data by copying the captured value and the given void function to an anonymous function using func::capval_target_t. More...

template<typename R , typename I , typename... A>
jau::function< R(A...)>	jau::bind_capval (I &&data, R(*func)(I &, A...)) noexcept
	Bind given data by moving the captured value and copying the given non-void function to an anonymous function using func::capval_target_t. More...

template<typename I , typename... A>
jau::function< void(A...)>	jau::bind_capval (I &&data, void(*func)(I &, A...)) noexcept
	Bind given data by moving the captured value and copying the given void function to an anonymous function using func::capval_target_t. More...

template<typename R , typename... A>
jau::function< R(A...)>	jau::bind_free (R(*func)(A...)) noexcept
	Bind given non-void free-function to an anonymous function using func::free_target_t. More...

template<typename... A>
jau::function< void(A...)>	jau::bind_free (void(*func)(A...)) noexcept
	Bind given void free-function to an anonymous function using func::free_target_t. More...

template<typename R , typename C , typename... A>
jau::function< R(A...)>	jau::bind_member (C base, R(C::mfunc)(A...)) noexcept
	Bind given class instance and non-void member function to an anonymous function using func_member_targer_t. More...

template<typename C , typename... A>
jau::function< void(A...)>	jau::bind_member (C base, void(C::mfunc)(A...)) noexcept
	Bind given class instance and void member function to an anonymous function using func_member_targer_t. More...

template<typename R , typename C0 , typename C1 , typename... A>
jau::function< R(A...)>	jau::bind_member (C1 base, R(C0::mfunc)(A...)) noexcept
	Bind given class instance and non-void member function to an anonymous function using func_member_targer_t. More...

template<typename C0 , typename C1 , typename... A>
jau::function< void(A...)>	jau::bind_member (C1 base, void(C0::mfunc)(A...)) noexcept
	Bind given class instance and void member function to an anonymous function using func_member_targer_t. More...

template<typename R , typename... A>
jau::function< R(A...)>	jau::bind_std (uint64_t id, std::function< R(A...)> func) noexcept
	Bind given non-void std::function to an anonymous function using func::std_target_t. More...

template<typename... A>
jau::function< void(A...)>	jau::bind_std (uint64_t id, std::function< void(A...)> func) noexcept
	Bind given void std::function to an anonymous function using func::std_target_t. More...

constexpr uint32_t	jau::number (const func::target_type rhs) noexcept

template<class R , class... A>
bool	jau::operator!= (const function< R(A...)> &lhs, std::nullptr_t) noexcept
	Unequal operator of jau::function<R(A...)> with a right-hand-side nullptr. More...

template<typename Rl , typename... Al, template< typename... > typename Fl = function, typename Rr , typename... Ar, template< typename... > typename Fr = function>
bool	jau::operator!= (const function< Rl(Al...)> &lhs, const function< Rr(Ar...)> &rhs) noexcept
	Unequal operator using two jau::function<R(A...)> types for both arguments. More...

template<class R , class... A>
bool	jau::operator!= (std::nullptr_t, const function< R(A...)> &rhs) noexcept
	Unequal operator of jau::function<R(A...)> with a left-hand-side nullptr. More...

template<class R , class... A>
bool	jau::operator== (const function< R(A...)> &lhs, std::nullptr_t) noexcept
	Equal operator of jau::function<R(A...)> with a right-hand-side nullptr. More...

template<typename Rl , typename... Al, template< typename... > class Fl = function, typename Rr , typename... Ar, template< typename... > class Fr = function, std::enable_if_t< !std::is_same_v< Fl< Rl(Al...)>, Fr< Rr(Ar...)> >, bool > = true>
bool	jau::operator== (const function< Rl(Al...)> &lhs, const function< Rr(Ar...)> &rhs) noexcept
	Equal operator using different jau::function<R(A...)> return and argument types for both arguments, always returns false. More...

template<class R , class... A>
bool	jau::operator== (std::nullptr_t, const function< R(A...)> &rhs) noexcept
	Equal operator of jau::function<R(A...)> with a left-hand-side nullptr. More...

std::string	jau::to_string (const func::target_type v) noexcept

Detailed Description

A general-purpose static-polymorphic function wrapper via jau::function<R(A...)>.

Supporting general-purpose polymorphic function wrapper via jau::function<R(A...)>.

Function Overview

Similar to std::function, jau::function<R(A...)> stores any callable target function solely described by its return type R and arguments types A... from any source, e.g. free functions, capturing and non-capturing lambda function, member functions.

jau::function<R(A...)> supports equality operations for all func::target_type source types, allowing to manage container of jau::functions, see limitations below.

If a jau::function contains no target, see jau::function<R(A...)>::is_null(), it is empty. Invoking the target of an empty jau::function is a no-operation and has no side effects.

jau::function satisfies the requirements of CopyConstructible, CopyAssignable, MoveConstructible and MoveAssignable.

Compared to std::function<R(A...)>, jau::function<R(A...)>

exposes the target function signature jau::type_info via jau::function::signature()
supports equality operations
supports Y combinator and deducing this lambda functions
self contained low memory, cache friendly, static polymorphic target function delegate_t<R, A...> storage, see implementation details
most operations are noexcept, except for the user given function invocation

Instances of jau::function can store, copy, move and invoke any of its callable targets

free functions
- factory bind_free()
  - includes non-capturing lambda
- constructor jau::function<R(A...)>::function(R(*func)(A...))
member functions
- factory bind_member()
- constructor `function(C *base, R(C::*mfunc)(A...))`
lambda functions
- capturing and non-capturing lambdas as jau::function using func::lambda_target_t
- constructor `template<typename L> function(L func)`
- see limitations on their equality operator w/o RTTI on `gcc`.
Y combinator and deducing this lambda functions
- factory bind_ylambda()
lambda alike functions using a captured data type by-reference
- factory bind_capref()
- constructor function(I* data_ptr, R(*func)(I*, A...))
lambda alike functions using a captured data type by value
- factory bind_capval()
- constructor copy function(const I& data, R(*func)(I&, A...))
- constructor move function(I&& data, R(*func)(I&, A...))
std::function
- factory bind_std()
- constructor function(uint64_t id, std::function<R(A...)> func)

Implementation Details

jau::function<R(A...)> holds the static polymorphic target function delegate_t<R, A...>,
which itself completely holds up to 24 bytes sized TriviallyCopyable target function objects to avoiding cache misses.

The following table shows the full memory footprint of the target function delegate_t<R, A...> storage,
which equals to jau::function<R(A...)> memory size as it only contains the instance of delegate_t<R, A...>.

Type	Signature	Target Function Size	`delegate_t<R, A...>` Size	Heap Size	Total Size	`TriviallyCopyable`
free	function<free, void ()>	8	48	0	48	true
member	function<member, int (int)>	16	48	0	48	true
lambda_plain	function<lambda, int (int)>	24	48	0	48	true
lambda_ref	function<lambda, int (int)>	24	48	0	48	true
lambda_copy	function<lambda, int (int)>	24	48	0	48	true
ylambda_plain	function<ylambda, int (int)>	24	48	0	48	true
capval (small)	function<capval, int (int)>	16	48	0	48	true
capval (big)	function<capval, int (int)>	48	48	48	96	true
capref	function<capref, int (int)>	16	48	0	48	true

Memory sizes are in bytes, data collected on a GNU/Linux arm64 system.

The detailed memory footprint can queried at runtime, see implementation of jau::function<R(A...)>::function::toString().

Static polymorphism is achieved by constructing the delegate_t<R, A...> instance via their func::target_type specific factories, see mapping at func::target_type.

For example the static func::member_target_t::delegate constructs its specific delegate_t<R, A...> by passing its data and required functions to func::delegate_t<R, A...>::make.
The latter is an overloaded template for trivial and non-trivial types and decides which memory is being used, e.g. the internal 24 bytes memory cache or heap if not fitting.

To support lambda identity for the equality operator, jau::type_info is being used either with Runtime Type Information (RTTI) if enabled or using Compile time type information (CTTI), see limitations below.

Function Usage

A detailed API usage is covered within test_functional.hpp and test_functional_perf.hpp, see function test00_usage().

Let's assume we like to bind to the following function prototype bool func(int), which results to jau::function<bool(int)>:

Free functions via constructor and jau::bind_free()
- Prologue
  typedef bool(*cfunc)(int); // to force non-capturing lambda into a free function template type deduction
  
  bool my_func(int v) { return 0 == v; }
  
  struct MyClass {
  
  static bool func(int v) { return 0 == v; }
  
  };
- Constructor function(R(*func)(A...))
  jau::function<bool(int)> func0 = my_func;
  
  jau::function<bool(int)> func1 = &MyClass:func;
  
  jau::function<bool(int)> func2 = (cfunc) ( [](int v) -> bool { // forced free via cast
  
  return 0 == v;
  
  } );
  
  jau::function
  Class template jau::function is a general-purpose static-polymorphic function wrapper.
  Definition: functional.hpp:1211
- Factory jau::bind_free(R(*func)(A...))
  jau::function<bool(int)> func0 = jau::bind_free(&MyClass:func);
  
  jau::function<bool(int)> func1 = jau::bind_free(my_func);
  
  jau::bind_free
  jau::function< R(A...)> bind_free(R(*func)(A...)) noexcept
  Bind given non-void free-function to an anonymous function using func::free_target_t.
  Definition: functional.hpp:1704
Class member functions via constructor and jau::bind_member()
- Prologue
  struct MyClass {
  
  bool m_func(int v) { return 0 == v; }
  
  };
  
  MyClass i1;
- Constructor function(C *base, R(C::*mfunc)(A...))
  jau::function<bool(int)> func(&i1, &MyClass::m_func);
- Factory jau::bind_member(C *base, R(C::*mfunc)(A...))
  jau::function<bool(int)> func = jau::bind_member(&i1, &MyClass::m_func);
  
  jau::bind_member
  jau::function< R(A...)> bind_member(C1 *base, R(C0::*mfunc)(A...)) noexcept
  Bind given class instance and non-void member function to an anonymous function using func_member_tar...
  Definition: functional.hpp:1627
Lambda functions via constructor
- Prologue
  int sum = 0;
- Stateless lambda, equivalent to bool(*)(int) function
  jau::function<bool(int)> func0 = [](int v) -> bool {
  
  return 0 == v;
  
  };
- Stateless by-value capturing lambda
  jau::function<bool(int)> func1 = [sum](int v) -> bool {
  
  return sum == v;
  
  };
- Stateful by-value capturing lambda mutating captured field
  jau::function<bool(int)> func1 = [sum](int v) mutable -> bool {
  
  sum += v;
  
  return 0 == v;
  
  };
- Stateless by-reference capturing lambda
  jau::function<bool(int)> func1 = [&sum](int v) -> bool {
  
  sum += v;
  
  return 0 == v;
  
  };
- Stateless by-reference capturing lambda assigning an auto lambda
  auto lambda_func = [&](int v) -> bool {
  
  sum += v;
  
  return 0 == v;
  
  };
  
  jau::function<bool(int)> func1 = lambda_func;
  
  jau::function<bool(int)> func2 = lambda_func;
  
  assert( func1 == func2 );
Y combinator and deducing this lambda functions via factory bind_ylambda()
- Stateless lambda receiving explicit this object parameter reference used for recursion using auto
  function<int(int)> f = function<int(int)>::bind_ylambda( [](auto& self, int x) -> int {
  
  if( 0 == x ) {
  
  return 1;
  
  } else {
  
  return x * self(x-1); // recursion, calling itself w/o explicitly passing `self`
  
  }
  
  } );
  
  assert( 24 == f(4) ); // `self` is bound to function<int(int)>::delegate_type `f.target`, `x` is 4
- or using explicit function<R(A...)>::delegate_type
  function<int(int)> f = function<int(int)>::bind_ylambda( [](function<int(int)>::delegate_type& self, int x) -> int {
  
  if( 0 == x ) {
  
  return 1;
  
  } else {
  
  return x * self(x-1); // recursion, calling itself w/o explicitly passing `self`
  
  }
  
  } );
  
  assert( 24 == f(4) ); // `self` is bound to function<int(int)>::delegate_type `f.target`, `x` is 4
Lambda alike capture by-reference to value via constructor and jau::bind_capref()
- Prologue
  struct big_data {
  
  int sum;
  
  };
  
  big_data data { 0 };
  
  typedef bool(*cfunc)(big_data*, int); // to force non-capturing lambda into a free function template type deduction
- Constructor function(I* data_ptr, R(*func)(I*, A...))
  function<int(int)> func(&data,
  
  (cfunc) ( [](big_data* data, int v) -> bool {
  
  stats_ptr->sum += v;
  
  return 0 == v;
  
  } ) );
- Factory jau::bind_capref(I* data_ptr, R(*func)(I*, A...))
  jau::function<bool(int)> func = jau::bind_capref(&data,
  
  (cfunc) ( [](big_data* data, int v) -> bool {
  
  stats_ptr->sum += v;
  
  return 0 == v;
  
  } ) );
  
  jau::bind_capref
  jau::function< R(A...)> bind_capref(I *data_ptr, R(*func)(I *, A...)) noexcept
  Bind given data by passing the captured reference (pointer) to the value and non-void function to an ...
  Definition: functional.hpp:1837
Lambda alike capture by-copy of value via constructor and jau::bind_capval()
- Constructor copy function(const I& data, R(*func)(I&, A...))
- Constructor move function(I&& data, R(*func)(I&, A...))
- Factory copy jau::bind_capval(const I& data, R(*func)(I&, A...))
- Factory move jau::bind_capval(I&& data, R(*func)(I&, A...))
  See example of Capture by-reference to value above.
std::function function via constructor and jau::bind_std()
- Prologue
  std::function<bool(int)> func_stdlambda = [](int i)->bool {
  
  return 0 == i;
  
  };
- Constructor function(uint64_t id, std::function<R(A...)> func)
  jau::function<bool(int)> func(100, func_stdlambda);
- Factory jau::bind_std(uint64_t id, std::function<R(A...)> func)
  jau::function<bool(int)> func = jau::bind_std(100, func_stdlambda);
  
  jau::bind_std
  jau::function< R(A...)> bind_std(uint64_t id, std::function< R(A...)> func) noexcept
  Bind given non-void std::function to an anonymous function using func::std_target_t.
  Definition: functional.hpp:1879

Function Limitations

Non unique lambda type names without RTTI using `gcc` or non `clang` compiler

Due to limitations of jau::make_ctti<R, L, A...>(), not using RTTI on gcc or non clang compiler will erroneously mistake different lambda functions defined within one function and using same function prototype R<A...> to be the same.

jau::type_info::limited_lambda_id will expose the potential limitation.

See CTTI lambda name limitations and limitations of jau::type_info.

Function Overview

Similar to std::function, jau::function<R(A...)> stores any callable target function solely described by its return type R and arguments types A... from any source, e.g. free functions, capturing and non-capturing lambda function, member functions,

jau::function<R(A...)> supports equality operations for all func::target_t source types, allowing to manage container of jau::functions.

See limitations below.

If a jau::function contains no target, see jau::function<R(A...)>::is_null(), it is empty. Invoking the target of an empty jau::function is a no-operation and has no side effects.

jau::function satisfies the requirements of CopyConstructible and CopyAssignable.

Compared to std::function<R(A...)>, jau::function<R(A...)>

supports equality operations,
supports capturing lambda functions
- See limitations on their equality operator w/o RTTI on `gcc`.
most operations are noexcept, except for the user given function invocation.
exposes the target function signature jau::type_info via jau::function::signature()

Instances of jau::function can store, copy, and invoke any of its callable targets

free functions
- bind_free()
  - includes non-capturing lambda
- constructor jau::function<R(A...)>::function(R(*func)(A...))
member functions
- bind_member()
- constructor `function(C *base, R(C::*mfunc)(A...))`
lambda functions
- constructor `template<typename L> function(L func)`
- see limitations on their equality operator w/o RTTI on `gcc`.
lambda alike functions using a captured data type by reference
- bind_capref()
- constructor function(I* data_ptr, R(*func)(I*, A...))
lambda alike functions using a captured data type by value
- bind_capval()
- constructor copy function(const I& data, R(*func)(I&, A...))
- constructor move function(I&& data, R(*func)(I&, A...))
std::function
- bind_std()
- constructor function(uint64_t id, std::function<R(A...)> func)

Function Usage

A detailed API usage is covered within test_functional01.cpp, see function test00_usage().

Let's assume we like to bind to the following function prototype bool func(int), which results to jau::function<bool(int)>:

Free functions via constructor and jau::bind_free()
- Prologue
  typedef bool(*cfunc)(int); // to force non-capturing lambda into a free function template type deduction
  
  bool my_func(int v) { return 0 == v; }
  
  struct MyClass {
  
  static bool func(int v) { return 0 == v; }
  
  };
- Constructor function(R(*func)(A...))
  jau::function<bool(int)> func0 = my_func;
  
  jau::function<bool(int)> func1 = &MyClass:func;
  
  jau::function<bool(int)> func2 = (cfunc) ( [](int v) -> bool { // forced free via cast
  
  return 0 == v;
  
  } );
- Bind jau::function<R(A...)> jau::bind_free(R(*func)(A...))
  jau::function<bool(int)> func0 = jau::bind_free(&MyClass:func);
  
  jau::function<bool(int)> func1 = jau::bind_free(my_func);
Class member functions via constructor and jau::bind_member()
- Prologue
  struct MyClass {
  
  bool m_func(int v) { return 0 == v; }
  
  };
  
  MyClass i1;
- Constructor function(C *base, R(C::*mfunc)(A...))
  jau::function<bool(int)> func(&i1, &MyClass::m_func);
- Bind jau::function<R(A...)> jau::bind_member(C *base, R(C::*mfunc)(A...))
  jau::function<bool(int)> func = jau::bind_member(&i1, &MyClass::m_func);
Lambda functions via constructor
- Prologue
  int sum = 0;
- Constructor template<typename L> function(L func)
  jau::function<bool(int)> func0 = [](int v) -> bool {
  
  return 0 == v;
  
  };
  
  jau::function<bool(int)> func1 = [&](int v) -> bool {
  
  sum += v;
  
  return 0 == v;
  
  };
  
  auto func2_stub = [&](int v) -> bool {
  
  sum += v;
  
  return 0 == v;
  
  };
  
  jau::function<bool(int)> func2 = func2_stub;
Lambda alike capture by reference to value via constructor and jau::bind_capref()
- Prologue
  struct big_data {
  
  int sum;
  
  };
  
  big_data data { 0 };
  
  typedef bool(*cfunc)(big_data*, int); // to force non-capturing lambda into a free function template type deduction
- Constructor function(I* data_ptr, R(*func)(I*, A...))
  function<int(int)> func(&data,
  
  (cfunc) ( [](big_data* data, int v) -> bool {
  
  stats_ptr->sum += v;
  
  return 0 == v;
  
  } ) );
- Bind jau::function<R(A...)> jau::bind_capref(I* data_ptr, R(*func)(I*, A...))
  jau::function<bool(int)> func = jau::bind_capref(&data,
  
  (cfunc) ( [](big_data* data, int v) -> bool {
  
  stats_ptr->sum += v;
  
  return 0 == v;
  
  } ) );
Lambda alike capture by copy of value via constructor and jau::bind_capval()
- Constructor copy function(const I& data, R(*func)(I&, A...))
- Constructor move function(I&& data, R(*func)(I&, A...))
- Bind copy jau::function<R(A...)> jau::bind_capval(const I& data, R(*func)(I&, A...))
- Bind move jau::function<R(A...)> jau::bind_capval(I&& data, R(*func)(I&, A...))
  See example of Capture by reference to value above.
std::function function via constructor and jau::bind_std()
- Prologue
  std::function<bool(int)> func_stdlambda = [](int i)->bool {
  
  return 0 == i;
  
  };
- Constructor function(uint64_t id, std::function<R(A...)> func)
  jau::function<bool(int)> func(100, func_stdlambda);
- Bind function<R(A...)> jau::bind_std(uint64_t id, std::function<R(A...)> func)
  jau::function<bool(int)> func = jau::bind_std(100, func_stdlambda);

Function Limitations

Non unique lambda type names without RTTI using `gcc` or non `clang` compiler

Due to limitations of jau::make_ctti<R, L, A...>(), not using RTTI on gcc or non clang compiler will erroneously mistake different lambda functions defined within one function and using same function prototype R<A...> to be the same.

jau::type_info::limited_lambda_id will expose the potential limitation.

See CTTI lambda name limitations and limitations of jau::type_info.

C++11 Capturing Lambda Restrictions using std::function

A capturing lambda in C++11 produces decoration code accessing the captured elements,
i.e. an anonymous helper class.
Due to this fact, the return type is an undefined lambda specific and hence std::function didn't support it when specified, probably.

 template<typename R, typename C, typename... A>
 inline function<R(A...)>
 bind_member(C *base, R(C::*mfunc)(A...)) {
     return ClassFunction<R, A...>(
             (void*)base,
             (void*)(*((void**)&mfunc)),
             [&](A... args)->R{ (base->*mfunc)(args...); });
              ^
              | Capturing lambda function-pointer are undefined!
 }

Capturing lambdas are supported by jau::function using func::lambda_target_t via constructor `template<typename L> function(L func)`, see above.

Enumeration Type Documentation

◆ target_type [1/2]

enum class jau::func::target_type : uint32_t

strong

func::target_type identifier for the target function delegate_t<R, A...> object, exposed by jau::function<R(A...)>::type().

See also: Function Overview

Enumerator
null	Denotes a func::null_target_t.
member	Denotes a func::member_target_t.
free	Denotes a func::free_target_t.
lambda	Denotes a func::lambda_target_t.
ylambda	Denotes a func::ylambda_target_t.
capval	Denotes a func::capval_target_t.
capref	Denotes a func::capref_target_t.
std	Denotes a func::std_target_t.
null	Denotes a func::null_target_t.
member	Denotes a func::member_target_t.
free	Denotes a func::free_target_t.
lambda	Denotes a func::lambda_target_t.
capval	Denotes a func::capval_target_t.
capref	Denotes a func::capref_target_t.
std	Denotes a func::std_target_t.

Definition at line 341 of file functional.hpp.

◆ target_type [2/2]

enum class jau::func::target_type : uint32_t

strong

func::target_type identifier for specializations of func::target_t used by jau::function<R(A...)>::type().

See also: Function Overview

Enumerator
null	Denotes a func::null_target_t.
member	Denotes a func::member_target_t.
free	Denotes a func::free_target_t.
lambda	Denotes a func::lambda_target_t.
ylambda	Denotes a func::ylambda_target_t.
capval	Denotes a func::capval_target_t.
capref	Denotes a func::capref_target_t.
std	Denotes a func::std_target_t.
null	Denotes a func::null_target_t.
member	Denotes a func::member_target_t.
free	Denotes a func::free_target_t.
lambda	Denotes a func::lambda_target_t.
capval	Denotes a func::capval_target_t.
capref	Denotes a func::capref_target_t.
std	Denotes a func::std_target_t.

Definition at line 277 of file functional2.hpp.

Function Documentation

◆ number()

constexpr uint32_t jau::number ( const func::target_type rhs )

constexprnoexcept

Definition at line 1196 of file functional.hpp.

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◆ to_string()

std::string jau::to_string ( const func::target_type v )

noexcept

Definition at line 535 of file basic_types.cpp.

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◆ operator==() [1/3]

template<typename Rl , typename... Al, template< typename... > class Fl = function, typename Rr , typename... Ar, template< typename... > class Fr = function, std::enable_if_t< !std::is_same_v< Fl< Rl(Al...)>, Fr< Rr(Ar...)> >, bool > = true>

bool jau::operator==	(	const function< Rl(Al...)> &	lhs,
		const function< Rr(Ar...)> &	rhs
	)

noexcept

Equal operator using different jau::function<R(A...)> return and argument types for both arguments, always returns false.

Equal operator using same jau::function<R(A...)> return and argument types for both arguments, returning actual result of equality operation.

Template Parameters

Rl	left function return type
Al	left function arguments
Fl	left function Fl<Rl(<Al...)>
Rr	right function return type
Ar	right function arguments
Fr	right function Fr<Rr(<Ar...)>

Parameters

lhs	left function Fl<Rl(<Al...)>
rhs	right function Fr<Rr(<Ar...)>

Returns: false

See also: function Overview; function Usage

Template Parameters

Rl	left function return type
Al	left function arguments
Fl	left function Fl<Rl(<Al...)>
Rr	right function return type
Ar	right function arguments
Fr	right function Fr<Rr(<Ar...)>

Parameters

lhs	left function Fl<Rl(<Al...)>
rhs	right function Fr<Rr(<Ar...)>

Returns: equality result of same type functions

See also: function Overview; function Usage

Definition at line 1518 of file functional.hpp.

◆ operator!=() [1/3]

template<typename Rl , typename... Al, template< typename... > typename Fl = function, typename Rr , typename... Ar, template< typename... > typename Fr = function>

bool jau::operator!=	(	const function< Rl(Al...)> &	lhs,
		const function< Rr(Ar...)> &	rhs
	)

noexcept

Unequal operator using two jau::function<R(A...)> types for both arguments.

Template Parameters

Rl	left function return type
Al	left function arguments
Fl	left function Fl<Rl(<Al...)>
Rr	right function return type
Ar	right function arguments
Fr	right function Fr<Rr(<Ar...)>

Parameters

lhs	left function Fl<Rl(<Al...)>
rhs	right function Fr<Rr(<Ar...)>

Returns: unequality result of same type functions

See also: function Overview; function Usage

Definition at line 1563 of file functional.hpp.

◆ operator==() [2/3]

template<class R , class... A>

bool jau::operator==	(	const function< R(A...)> &	lhs,
		std::nullptr_t
	)

noexcept

Equal operator of jau::function<R(A...)> with a right-hand-side nullptr.

Template Parameters

R	left function return type
A	left function arguments

Parameters

lhs	left function

Returns: true if function instance contains no function, i.e. !lhs negated function bool operator.

Definition at line 1574 of file functional.hpp.

◆ operator!=() [2/3]

template<class R , class... A>

bool jau::operator!=	(	const function< R(A...)> &	lhs,
		std::nullptr_t
	)

noexcept

Unequal operator of jau::function<R(A...)> with a right-hand-side nullptr.

Template Parameters

R	left function return type
A	left function arguments

Parameters

lhs	left function

Returns: true if function instance contains a function, i.e. lhs function bool operator.

Definition at line 1585 of file functional.hpp.

◆ operator==() [3/3]

template<class R , class... A>

bool jau::operator==	(	std::nullptr_t	,
		const function< R(A...)> &	rhs
	)

noexcept

Equal operator of jau::function<R(A...)> with a left-hand-side nullptr.

Template Parameters

R	right function return type
A	right function arguments

Parameters

rhs	right function

Returns: true if function instance contains no function, i.e. !lhs negated function bool operator.

Definition at line 1596 of file functional.hpp.

◆ operator!=() [3/3]

template<class R , class... A>

bool jau::operator!=	(	std::nullptr_t	,
		const function< R(A...)> &	rhs
	)

noexcept

Unequal operator of jau::function<R(A...)> with a left-hand-side nullptr.

Template Parameters

R	right function return type
A	right function arguments

Parameters

rhs	right function

Returns: true if function instance contains a function, i.e. lhs function bool operator.

Definition at line 1607 of file functional.hpp.

◆ bind_member() [1/4]

template<typename R , typename C0 , typename C1 , typename... A>

jau::function< R(A...)> jau::bind_member	(	C1 *	base,
		R(C0::*)(A...)	mfunc
	)

inlinenoexcept

Bind given class instance and non-void member function to an anonymous function using func_member_targer_t.

Template Parameters

R	function return type
C0	class type holding the member-function
C1	class derived from C0 or C0 of this base-pointer used to invoke the member-function
A	function arguments

Parameters

base	class instance `this` pointer
mfunc	member-function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for member function; function Overview; function Usage

Examples: dbt_peripheral00.cpp, test_functional.hpp, and test_functional_perf.hpp.

Definition at line 1627 of file functional.hpp.

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◆ bind_member() [2/4]

template<typename R , typename C , typename... A>

jau::function< R(A...)> jau::bind_member	(	C *	base,
		R(C::*)(A...)	mfunc
	)

inlinenoexcept

Bind given class instance and non-void member function to an anonymous function using func_member_targer_t.

Template Parameters

R	function return type
C	class type holding the member-function and of this base pointer
A	function arguments

Parameters

base	class instance `this` pointer
mfunc	member-function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for member function; function Overview; function Usage

Definition at line 1647 of file functional.hpp.

◆ bind_member() [3/4]

template<typename C0 , typename C1 , typename... A>

jau::function< void(A...)> jau::bind_member	(	C1 *	base,
		void(C0::*)(A...)	mfunc
	)

inlinenoexcept

Bind given class instance and void member function to an anonymous function using func_member_targer_t.

Template Parameters

C0	class type holding the member-function
C1	class derived from C0 or C0 of this base-pointer used to invoke the member-function
A	function arguments

Parameters

base	class instance `this` pointer
mfunc	member-function with `A...` arguments.

Returns: anonymous function

See also: function constructor for member function; function Overview; function Usage

Definition at line 1667 of file functional.hpp.

◆ bind_member() [4/4]

template<typename C , typename... A>

jau::function< void(A...)> jau::bind_member	(	C *	base,
		void(C::*)(A...)	mfunc
	)

inlinenoexcept

Bind given class instance and void member function to an anonymous function using func_member_targer_t.

Template Parameters

C	class type holding the member-function and of this base pointer
A	function arguments

Parameters

base	class instance `this` pointer
mfunc	member-function with `A...` arguments.

Returns: anonymous function

See also: function constructor for member function; function Overview; function Usage

Definition at line 1686 of file functional.hpp.

◆ bind_free() [1/2]

template<typename R , typename... A>

jau::function< R(A...)> jau::bind_free ( R(*)(A...) func )

inlinenoexcept

Bind given non-void free-function to an anonymous function using func::free_target_t.

Template Parameters

R	function return type
A	function arguments

Parameters

func	free-function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for free function; function Overview; function Usage

Examples: test_functional.hpp, and test_functional_perf.hpp.

Definition at line 1704 of file functional.hpp.

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◆ bind_free() [2/2]

template<typename... A>

jau::function< void(A...)> jau::bind_free ( void(*)(A...) func )

inlinenoexcept

Bind given void free-function to an anonymous function using func::free_target_t.

Template Parameters

A	function arguments

Parameters

func	free-function with `A...` arguments.

Returns: anonymous function

See also: function constructor for free function; function Overview; function Usage

Definition at line 1721 of file functional.hpp.

◆ bind_capval() [1/4]

template<typename R , typename I , typename... A>

jau::function< R(A...)> jau::bind_capval	(	const I &	data,
		R(*)(I &, A...)	func
	)

inlinenoexcept

Bind given data by copying the captured value and the given non-void function to an anonymous function using func::capval_target_t.

const I& data will be copied into func::capval_target_t and hence captured by-copy.

The function invocation will have the reference of the copied data being passed to the target function for efficiency.

Template Parameters

R	function return type
I	typename holding the captured data used by the function
A	function arguments

Parameters

data	data type instance holding the captured data
func	function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for copying capturing value; function Overview; function Usage

const I& data will be copied into func::capval_target_t and hence captured by copy.

The function invocation will have the reference of the copied data being passed to the target function for efficiency.

Template Parameters

R	function return type
I	typename holding the captured data used by the function
A	function arguments

Parameters

data	data type instance holding the captured data
func	function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for copying capturing value; function Overview; function Usage

Examples: test_functional.hpp, and test_functional_perf.hpp.

Definition at line 1745 of file functional.hpp.

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◆ bind_capval() [2/4]

template<typename I , typename... A>

jau::function< void(A...)> jau::bind_capval	(	const I &	data,
		void(*)(I &, A...)	func
	)

inlinenoexcept

Bind given data by copying the captured value and the given void function to an anonymous function using func::capval_target_t.

const I& data will be copied into func::capval_target_t and hence captured by-copy.

The function invocation will have the reference of the copied data being passed to the target function for efficiency.

Template Parameters

I	typename holding the captured data used by the function
A	function arguments

Parameters

data	data type instance holding the captured data
func	function with `A...` arguments.

Returns: anonymous function

See also: function constructor for copying capturing value; function Overview; function Usage

const I& data will be copied into func::capval_target_t and hence captured by copy.

The function invocation will have the reference of the copied data being passed to the target function for efficiency.

Template Parameters

I	typename holding the captured data used by the function
A	function arguments

Parameters

data	data type instance holding the captured data
func	function with `A...` arguments.

Returns: anonymous function

See also: function constructor for copying capturing value; function Overview; function Usage

Definition at line 1768 of file functional.hpp.

◆ bind_capval() [3/4]

template<typename R , typename I , typename... A>

jau::function< R(A...)> jau::bind_capval	(	I &&	data,
		R(*)(I &, A...)	func
	)

inlinenoexcept

Bind given data by moving the captured value and copying the given non-void function to an anonymous function using func::capval_target_t.

I&& data will be moved into func::capval_target_t.

The function invocation will have the reference of the moved data being passed to the target function for efficiency.

Template Parameters

R	function return type
I	typename holding the captured data used by the function
A	function arguments

Parameters

data	data type instance holding the captured data
func	function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for moving capturing value; function Overview; function Usage

Definition at line 1792 of file functional.hpp.

◆ bind_capval() [4/4]

template<typename I , typename... A>

jau::function< void(A...)> jau::bind_capval	(	I &&	data,
		void(*)(I &, A...)	func
	)

inlinenoexcept

Bind given data by moving the captured value and copying the given void function to an anonymous function using func::capval_target_t.

I&& data will be moved into func::capval_target_t.

The function invocation will have the reference of the moved data being passed to the target function for efficiency.

Template Parameters

I	typename holding the captured data used by the function
A	function arguments

Parameters

data	data type instance holding the captured data
func	function with `A...` arguments.

Returns: anonymous function

See also: function constructor for moving capturing value; function Overview; function Usage

Definition at line 1815 of file functional.hpp.

◆ bind_capref() [1/2]

template<typename R , typename I , typename... A>

jau::function< R(A...)> jau::bind_capref	(	I *	data_ptr,
		R()(I , A...)	func
	)

inlinenoexcept

Bind given data by passing the captured reference (pointer) to the value and non-void function to an anonymous function using func::capref_target_t.

The function invocation will have the reference of the data being passed to the target function.

Template Parameters

R	function return type
I	typename holding the captured data used by the function
A	function arguments

Parameters

data_ptr	data type reference to instance holding the captured data
func	function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for capturing reference; function Overview; function Usage

Examples: test_functional.hpp, and test_functional_perf.hpp.

Definition at line 1837 of file functional.hpp.

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◆ bind_capref() [2/2]

template<typename I , typename... A>

jau::function< void(A...)> jau::bind_capref	(	I *	data_ptr,
		void()(I , A...)	func
	)

inlinenoexcept

Bind given data by passing the captured reference (pointer) to the value and void function to an anonymous function using func::capref_target_t.

The function invocation will have the reference of the data being passed to the target function.

Template Parameters

I	typename holding the captured data used by the function
A	function arguments

Parameters

data_ptr	data type reference to instance holding the captured data
func	function with `A...` arguments.

Returns: anonymous function

See also: function constructor for capturing reference; function Overview; function Usage

Definition at line 1858 of file functional.hpp.

◆ bind_std() [1/2]

template<typename R , typename... A>

jau::function< R(A...)> jau::bind_std	(	uint64_t	id,
		std::function< R(A...)>	func
	)

inlinenoexcept

Bind given non-void std::function to an anonymous function using func::std_target_t.

Notable, instance is holding the given unique uint64_t identifier to allow implementing the equality operator w/o RTTI, not supported by std::function.

Template Parameters

R	function return type
A	function arguments

Parameters

func	free-function with `R` return value and `A...` arguments.

Returns: anonymous function

See also: function constructor for std::function; function Overview; function Usage

Examples: test_functional.hpp, and test_functional_perf.hpp.

Definition at line 1879 of file functional.hpp.

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◆ bind_std() [2/2]

template<typename... A>

jau::function< void(A...)> jau::bind_std	(	uint64_t	id,
		std::function< void(A...)>	func
	)

inlinenoexcept

Bind given void std::function to an anonymous function using func::std_target_t.

Notable, instance is holding the given unique uint64_t identifier to allow implementing the equality operator w/o RTTI, not supported by std::function.

Template Parameters

A	function arguments

Parameters

func	free-function with `A...` arguments.

Returns: anonymous function

See also: function constructor for std::function; function Overview; function Usage

Definition at line 1899 of file functional.hpp.

Namespaces

Classes

Enumerations

Functions

Detailed Description

Function Overview

Implementation Details

Function Usage

Function Limitations

Non unique lambda type names without RTTI using gcc or non clang compiler

Function Overview

Function Usage

Function Limitations

Non unique lambda type names without RTTI using gcc or non clang compiler

C++11 Capturing Lambda Restrictions using std::function

Enumeration Type Documentation

◆ target_type [1/2]

◆ target_type [2/2]

Function Documentation

◆ number()

◆ to_string()

◆ operator==() [1/3]

◆ operator!=() [1/3]

◆ operator==() [2/3]

◆ operator!=() [2/3]

◆ operator==() [3/3]

◆ operator!=() [3/3]

◆ bind_member() [1/4]

◆ bind_member() [2/4]

◆ bind_member() [3/4]

◆ bind_member() [4/4]

◆ bind_free() [1/2]

◆ bind_free() [2/2]

◆ bind_capval() [1/4]

◆ bind_capval() [2/4]

◆ bind_capval() [3/4]

◆ bind_capval() [4/4]

◆ bind_capref() [1/2]

◆ bind_capref() [2/2]

◆ bind_std() [1/2]

◆ bind_std() [2/2]

Non unique lambda type names without RTTI using `gcc` or non `clang` compiler

Non unique lambda type names without RTTI using `gcc` or non `clang` compiler