exptl::composable< Fn > Class Template Reference

Wraps around a callable object to provide function composition. More...

Public Member Functions
	composable (Fn fn)
	Creates a composable<Fn> wrapping the callable fn. More...
template<typename Fn2 >
auto	operator+ (Fn2 rhs) const
	Returns the composition of this composable and rhs. More...
template<typename... Args>
decltype(auto)	operator() (Args &&...args)
	Calls the wrapped function the provided arguments. More...
template<typename... Args>
decltype(auto)	operator() (Args &&...args) const
	Calls the wrapped function with the provided arguments. More...

Detailed Description

template<typename Fn>
class exptl::composable< Fn >

Wraps around a callable object to provide function composition.

Template Parameters

Fn	The callable object type.

Constructor & Destructor Documentation

composable()

template<typename Fn >

exptl::composable< Fn >::composable ( Fn  fn )

inline

Creates a composable<Fn> wrapping the callable fn.

Parameters

fn	The callable object to wrap.

: fn{fn} {}

Member Function Documentation

operator()() [1/2]

template<typename Fn >

template<typename... Args>

decltype(auto) exptl::composable< Fn >::operator() ( Args &&...  args )

inline

Calls the wrapped function the provided arguments.

Template Parameters

Args	Type of the arguments to pass to the wrapped function.

Parameters

args	The arguments to pass to the wrapped function.

Returns

The result of calling the wrapped function.

    {
        return std::invoke(fn, std::forward<Args>(args)...);
    }

operator()() [2/2]

template<typename Fn >

template<typename... Args>

decltype(auto) exptl::composable< Fn >::operator() ( Args &&...  args ) const

inline

Calls the wrapped function with the provided arguments.

Only allowed when the wrapped callable is equality preserving.

Template Parameters

Args	Type of the arguments to pass to the wrapped function.

Parameters

args	The arguments to pass to the wrapped function.

Returns

The result of calling the wrapped function.

    {
        return std::invoke(fn, std::forward<Args>(args)...);
    }

operator+()

template<typename Fn >

template<typename Fn2 >

auto exptl::composable< Fn >::operator+ ( Fn2  rhs ) const

inline

Returns the composition of this composable and rhs.

Given that fn is the currently wrapped callable, returns a composable that wraps around a callable which invokes rhs(fn(args)) when called with the arguments args.

Template Parameters

Fn2	Type of the callable object to compose with.

Parameters

rhs	The callable object to compose with.

    {
        auto lambda{
          [=, fn{fn}](auto &&...args) mutable -> decltype(auto)
          {
              return std::invoke(
                rhs, std::invoke(fn, std::forward<decltype(args)>(args)...));
          }};
 
        return composable<decltype(lambda)>{lambda};
    }