PApply< SIG, VAL > Class Template Reference

#include "lib/meta/function-closure.hpp"

Description

template<typename SIG, typename VAL>
class lib::meta::func::PApply< SIG, VAL >

Partial function application Takes a function and a value tuple, using the latter to close function arguments either from the front (left) or aligned to the end of the function argument list.

Result is a "reduced" function, expecting only the remaining "un-closed" arguments at invocation.

Template Parameters

SIG	signature of the function to be closed, either as function reference type or std::function object
VAL	type sequence describing the tuple of values used for closing arguments

Note

the construction of this helper template does not verify or match types to the signature. In case of mismatch, you'll get a compilation failure from std::bind (which can be confusing)

Todo:

11/2023 started with modernising these functor utils. The most relevant bindFirst() / bindLast() operations do no longer rely on the PApply template. There is however the more general case of binding multiple arguments, which is still used at a few places. Possibly PApply should be rewritten from scratch, using modern tooling.

Definition at line 558 of file function-closure.hpp.

Public Types
typedef function< typename BuildFunType< Ret, ArgsL >::Sig >	LeftReducedFunc
typedef function< typename BuildFunType< Ret, ArgsR >::Sig >	RightReducedFunc

Static Public Member Functions
static RightReducedFunc	bindBack (SIG const &f, Tuple< ValTypes > const &arg)
	do a partial function application, closing the last arguments f(a,b,c)->res + (b,c) yields f(a)->res More...
static LeftReducedFunc	bindFront (SIG const &f, Tuple< ValTypes > const &arg)
	do a partial function application, closing the first arguments f(a,b,c)->res + (a,b) yields f(c)->res More...

Private Types
enum	{   ARG_CNT = count<ArgsList>::value,   VAL_CNT = count<ValList> ::value,   ROFFSET = (VAL_CNT < ARG_CNT)? ARG_CNT-VAL_CNT : 0 }
typedef _Fun< SIG >::Args	Args
typedef Types< LeftReduced >::Seq	ArgsL
typedef Args::List	ArgsList
typedef Types< RightReduced >::Seq	ArgsR
using	BuildL = TupleConstructor< LeftReplacedTypes, IdxSelectorL >
using	BuildR = TupleConstructor< RightReplacedTypes, IdxSelectorR >
template<class SRC , class TAR , size_t i>
using	IdxSelectorL = typename PartiallyInitTuple< SRC, TAR, 0 >::template IndexMapper< i >
template<class SRC , class TAR , size_t i>
using	IdxSelectorR = typename PartiallyInitTuple< SRC, TAR, ROFFSET >::template IndexMapper< i >
typedef func::PlaceholderTuple< RightReduced >::List	LeadingPlaceholders
typedef Splice< ArgsList, ValList >::Back	LeftReduced
typedef Splice< ArgsList, TrailingPlaceholders, VAL_CNT >::List	LeftReplaced
using	LeftReplacedArgs = Tuple< LeftReplacedTypes >
	Tuple to hold all argument values, starting from left. More...
typedef Types< LeftReplaced >::Seq	LeftReplacedTypes
typedef _Fun< SIG >::Ret	Ret
typedef Splice< ArgsList, ValList, ROFFSET >::Front	RightReduced
typedef Splice< ArgsList, LeadingPlaceholders, 0 >::List	RightReplaced
using	RightReplacedArgs = Tuple< RightReplacedTypes >
	Tuple to hold all argument values, aligned to the end of the function argument list. More...
typedef Types< RightReplaced >::Seq	RightReplacedTypes
typedef func::PlaceholderTuple< LeftReduced >::List	TrailingPlaceholders
typedef VAL::List	ValList
typedef Types< ValList >::Seq	ValTypes

Member Typedef Documentation

LeftReplacedArgs

using LeftReplacedArgs = Tuple<LeftReplacedTypes>

private

Tuple to hold all argument values, starting from left.

Any remaining positions behind the substitute values are occupied by binding placeholders

Definition at line 608 of file function-closure.hpp.

RightReplacedArgs

using RightReplacedArgs = Tuple<RightReplacedTypes>

private

Tuple to hold all argument values, aligned to the end of the function argument list.

Any remaining positions before the substitute values are occupied by binding placeholders

Definition at line 612 of file function-closure.hpp.

Member Function Documentation

bindFront()

static LeftReducedFunc bindFront ( SIG const &  f, Tuple< ValTypes > const &  arg  )

inlinestatic

do a partial function application, closing the first arguments
f(a,b,c)->res + (a,b) yields f(c)->res

Parameters

f	function, function pointer or functor
arg	value tuple, used to close function arguments starting from left

Returns

new function object, holding copies of the values and using them at the closed arguments; on invocation, only the remaining arguments need to be supplied.

Definition at line 629 of file function-closure.hpp.

bindBack()

static RightReducedFunc bindBack ( SIG const &  f, Tuple< ValTypes > const &  arg  )

inlinestatic

do a partial function application, closing the last arguments
f(a,b,c)->res + (b,c) yields f(a)->res

Parameters

f	function, function pointer or functor
arg	value tuple, used to close function arguments starting from right

Returns

new function object, holding copies of the values and using them at the closed arguments; on invocation, only the remaining arguments need to be supplied.

Definition at line 644 of file function-closure.hpp.

Collaboration diagram for PApply< SIG, VAL >:

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

• function-closure.hpp