CRTP base class providing common adapter operations. More...

#include <functional_adapters.hpp>

Public Member Functions
template<typename Pred>
constexpr auto	Filter (Pred predicate) const noexcept(noexcept(FilterAdapter< Derived, Pred >(GetDerived().begin(), GetDerived().end(), std::move(predicate))))
	Chains another filter operation on top of this iterator.
template<typename Func>
constexpr auto	Map (Func transform) const noexcept(noexcept(MapAdapter< Derived, Func >(GetDerived().begin(), GetDerived().end(), std::move(transform))))
	Transforms each element using the given function.
constexpr auto	Take (size_t count) const noexcept(noexcept(TakeAdapter< Derived >(GetDerived().begin(), GetDerived().end(), count)))
	Limits the number of elements to at most count.
constexpr auto	Skip (size_t count) const noexcept(noexcept(SkipAdapter< Derived >(GetDerived().begin(), GetDerived().end(), count)))
	Skips the first count elements.
template<typename Pred>
constexpr auto	TakeWhile (Pred predicate) const noexcept(noexcept(TakeWhileAdapter< Derived, Pred >(GetDerived().begin(), GetDerived().end(), std::move(predicate))))
	Takes elements while a predicate is true.
template<typename Pred>
constexpr auto	SkipWhile (Pred predicate) const noexcept(noexcept(SkipWhileAdapter< Derived, Pred >(GetDerived().begin(), GetDerived().end(), std::move(predicate))))
	Skips elements while a predicate is true.
constexpr auto	Enumerate () const noexcept(noexcept(EnumerateAdapter< Derived >(GetDerived().begin(), GetDerived().end())))
	Adds an index to each element.
template<typename Func>
constexpr auto	Inspect (Func inspector) const noexcept(noexcept(InspectAdapter< Derived, Func >(GetDerived().begin(), GetDerived().end(), std::move(inspector))))
	Observes each element without modifying it.
constexpr auto	StepBy (size_t step) const noexcept(noexcept(StepByAdapter< Derived >(GetDerived().begin(), GetDerived().end(), step)))
	Takes every Nth element.
template<typename OtherIter>
constexpr auto	Chain (OtherIter begin, OtherIter end) const noexcept(noexcept(ChainAdapter< Derived, OtherIter >(GetDerived().begin(), GetDerived().end(), std::move(begin), std::move(end))))
	Chains another range after this one.
template<typename R>
constexpr auto	Chain (R &range) const noexcept(noexcept(ChainAdapter< Derived, std::ranges::iterator_t< R > >(GetDerived().begin(), GetDerived().end(), range)))
	Chains another range after this one.
template<typename R>
constexpr auto	Chain (const R &range) const noexcept(noexcept(ChainAdapter< Derived, std::ranges::iterator_t< const R > >(GetDerived().begin(), GetDerived().end(), range)))
	Chains another range after this one.
constexpr auto	Reverse () const noexcept(noexcept(ReverseAdapter< Derived >(GetDerived().begin(), GetDerived().end())))
	Reverses the order of elements.
constexpr auto	Slide (size_t window_size) const noexcept(noexcept(SlideAdapter< Derived >(GetDerived().begin(), GetDerived().end(), window_size)))
	Creates sliding windows over elements.
constexpr auto	Stride (size_t stride) const noexcept(noexcept(StrideAdapter< Derived >(GetDerived().begin(), GetDerived().end(), stride)))
	Takes every Nth element with stride.
template<typename OtherIter>
constexpr auto	Zip (OtherIter begin, OtherIter end) const noexcept(noexcept(ZipAdapter< Derived, OtherIter >(GetDerived().begin(), GetDerived().end(), std::move(begin), std::move(end))))
	Zips another range with this one.
template<typename R>
constexpr auto	Zip (R &range) const noexcept(noexcept(ZipAdapter< Derived, std::ranges::iterator_t< R > >(GetDerived().begin(), GetDerived().end(), range)))
	Zips another range with this one.
template<typename R>
constexpr auto	Zip (const R &range) const noexcept(noexcept(ZipAdapter< Derived, std::ranges::iterator_t< const R > >(GetDerived().begin(), GetDerived().end(), range)))
	Zips another range with this one.
template<typename Action>
constexpr void	ForEach (const Action &action) const
	Terminal operation: applies an action to each element.
template<typename T, typename Folder>
constexpr T	Fold (T init, const Folder &folder) const
	Terminal operation: reduces elements to a single value using a folder function.
template<typename Pred>
constexpr auto	Find (const Pred &predicate) const
	Terminal operation: finds the first element satisfying a predicate.
template<typename Pred>
constexpr size_t	CountIf (const Pred &predicate) const
	Terminal operation: counts elements satisfying a predicate.
template<typename Pred>
constexpr auto	Partition (const Pred &predicate) const
	Terminal operation: partitions elements into two groups based on a predicate.
template<typename Pred, typename Allocator> requires std::same_as<typename Allocator::value_type, std::iter_value_t<Derived>>
constexpr auto	PartitionWith (const Pred &predicate, Allocator allocator) const
	Terminal operation: partitions elements with a custom allocator.
template<typename KeyFunc>
constexpr auto	MaxBy (const KeyFunc &key_func) const
	Terminal operation: finds the element with the maximum value according to a key function.
template<typename KeyFunc>
constexpr auto	MinBy (const KeyFunc &key_func) const
	Terminal operation: finds the element with the minimum value according to a key function.
template<typename KeyFunc>
constexpr auto	GroupBy (const KeyFunc &key_func) const
	Terminal operation: groups elements by a key function.
template<typename KeyFunc, typename MapAllocator, typename ValueAllocator>
constexpr auto	GroupByWith (const KeyFunc &key_func, MapAllocator map_allocator, ValueAllocator value_allocator) const
	Terminal operation: groups elements by key with custom allocators.
constexpr auto	Collect () const
	Terminal operation: collects all elements into a vector.
template<typename Allocator>
constexpr auto	CollectWith (Allocator allocator={}) const
	Terminal operation: collects all elements into a vector with a custom allocator.
constexpr auto	CollectWith (std::pmr::memory_resource *resource) const
	Terminal operation: collects all elements into a vector with a specific memory resource.
auto	CollectWith (std::nullptr_t) const =delete
template<typename OutIt>
constexpr void	Into (OutIt out) const
	Terminal operation: writes all elements into an output iterator.
template<typename Pred>
constexpr bool	Any (const Pred &predicate) const
	Terminal operation: checks if any element satisfies a predicate.
template<typename Pred>
constexpr bool	All (const Pred &predicate) const
	Terminal operation: checks if all elements satisfy a predicate.
template<typename Pred>
constexpr bool	None (const Pred &predicate) const
	Terminal operation: checks if no elements satisfy a predicate.

Protected Member Functions
constexpr Derived &	GetDerived () noexcept
	Gets reference to derived class instance.
constexpr const Derived &	GetDerived () const noexcept
	Gets const reference to derived class instance.

Detailed Description

template<typename Derived>
class helios::utils::FunctionalAdapterBase< Derived >

CRTP base class providing common adapter operations.

Provides chaining methods (Filter, Map, Take, Skip, etc.) that can be used by any derived adapter class. Uses CRTP pattern to return the correct derived type.

Template Parameters

Derived The derived adapter class

Definition at line 3583 of file functional_adapters.hpp.

Member Function Documentation

◆ All()

template<typename Derived>

template<typename Pred>

bool helios::utils::FunctionalAdapterBase< Derived >::All ( const Pred & predicate ) const

nodiscardconstexpr

Terminal operation: checks if all elements satisfy a predicate.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to test elements

Returns: True if all elements satisfy the predicate, false otherwise

Definition at line 4393 of file functional_adapters.hpp.

◆ Any()

template<typename Derived>

template<typename Pred>

bool helios::utils::FunctionalAdapterBase< Derived >::Any ( const Pred & predicate ) const

nodiscardconstexpr

Terminal operation: checks if any element satisfies a predicate.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to test elements

Returns: True if any element satisfies the predicate, false otherwise

Definition at line 4375 of file functional_adapters.hpp.

◆ Chain() [1/3]

template<typename Derived>

template<typename R>

auto helios::utils::FunctionalAdapterBase< Derived >::Chain ( const R & range ) const

inlinenodiscardconstexprnoexcept

Chains another range after this one.

Template Parameters

R	Range type of the other adapter

Parameters

range The other range to chain

Returns: ChainAdapter that yields elements from both ranges

Definition at line 3743 of file functional_adapters.hpp.

◆ Chain() [2/3]

template<typename Derived>

template<typename OtherIter>

auto helios::utils::FunctionalAdapterBase< Derived >::Chain	(	OtherIter	begin,
		OtherIter	end ) const

inlinenodiscardconstexprnoexcept

Chains another range after this one.

Template Parameters

OtherIter Iterator type of the other adapter

Parameters

begin	Begin iterator of the other adapter
end	End iterator of the other adapter

Returns: ChainAdapter that yields elements from both ranges

Definition at line 3712 of file functional_adapters.hpp.

◆ Chain() [3/3]

template<typename Derived>

template<typename R>

auto helios::utils::FunctionalAdapterBase< Derived >::Chain ( R & range ) const

inlinenodiscardconstexprnoexcept

Chains another range after this one.

Template Parameters

R	Range type of the other adapter

Parameters

range The other range to chain

Returns: ChainAdapter that yields elements from both ranges

Definition at line 3729 of file functional_adapters.hpp.

◆ Collect()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Collect ( ) const

nodiscardconstexpr

Terminal operation: collects all elements into a vector.

Returns: Vector containing all elements

Definition at line 4333 of file functional_adapters.hpp.

◆ CollectWith() [1/3]

template<typename Derived>

template<typename Allocator>

auto helios::utils::FunctionalAdapterBase< Derived >::CollectWith ( Allocator allocator = {} ) const

nodiscardconstexpr

Terminal operation: collects all elements into a vector with a custom allocator.

Template Parameters

Allocator Allocator type

Parameters

allocator Allocator to use for the vector

Returns: Vector containing all elements

Definition at line 4346 of file functional_adapters.hpp.

◆ CollectWith() [2/3]

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::CollectWith ( std::nullptr_t ) const

delete

◆ CollectWith() [3/3]

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::CollectWith ( std::pmr::memory_resource * resource ) const

nodiscardconstexpr

Terminal operation: collects all elements into a vector with a specific memory resource.

Parameters

resource Memory resource to use for the vector

Returns: Vector containing all elements

Definition at line 4359 of file functional_adapters.hpp.

◆ CountIf()

template<typename Derived>

template<typename Pred>

size_t helios::utils::FunctionalAdapterBase< Derived >::CountIf ( const Pred & predicate ) const

nodiscardconstexpr

Terminal operation: counts elements satisfying a predicate.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to test elements

Returns: Number of elements that satisfy the predicate

Definition at line 4099 of file functional_adapters.hpp.

◆ Enumerate()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Enumerate ( ) const

inlinenodiscardconstexprnoexcept

Adds an index to each element.

Returns: EnumerateAdapter that pairs indices with values

Definition at line 3671 of file functional_adapters.hpp.

◆ Filter()

template<typename Derived>

template<typename Pred>

auto helios::utils::FunctionalAdapterBase< Derived >::Filter ( Pred predicate ) const

inlinenodiscardconstexprnoexcept

Chains another filter operation on top of this iterator.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to filter elements

Returns: FilterAdapter that applies this adapter then filters

Definition at line 3592 of file functional_adapters.hpp.

◆ Find()

template<typename Derived>

template<typename Pred>

auto helios::utils::FunctionalAdapterBase< Derived >::Find ( const Pred & predicate ) const

nodiscardconstexpr

Terminal operation: finds the first element satisfying a predicate.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to test elements

Returns: Optional or pointer to the element with maximum key, based on the iterator type

Definition at line 4069 of file functional_adapters.hpp.

◆ Fold()

template<typename Derived>

template<typename T, typename Folder>

T helios::utils::FunctionalAdapterBase< Derived >::Fold	(	T	init,
		const Folder &	folder ) const

nodiscardconstexpr

Terminal operation: reduces elements to a single value using a folder function.

Template Parameters

T	Accumulator type
Folder	Function type that combines accumulator with each element

Parameters

init	Initial accumulator value
folder	Function to fold elements

Returns: Final accumulated value

Definition at line 4050 of file functional_adapters.hpp.

◆ ForEach()

template<typename Derived>

template<typename Action>

void helios::utils::FunctionalAdapterBase< Derived >::ForEach ( const Action & action ) const

constexpr

Terminal operation: applies an action to each element.

Template Parameters

Action Function type that processes each element

Parameters

action Function to apply to each element

Definition at line 4037 of file functional_adapters.hpp.

◆ GetDerived() [1/2]

template<typename Derived>

const Derived & helios::utils::FunctionalAdapterBase< Derived >::GetDerived ( ) const

inlinenodiscardconstexprprotectednoexcept

Gets const reference to derived class instance.

Returns: Const reference to derived class

Definition at line 4030 of file functional_adapters.hpp.

◆ GetDerived() [2/2]

template<typename Derived>

Derived & helios::utils::FunctionalAdapterBase< Derived >::GetDerived ( )

inlinenodiscardconstexprprotectednoexcept

Gets reference to derived class instance.

Returns: Reference to derived class

Definition at line 4022 of file functional_adapters.hpp.

◆ GroupBy()

template<typename Derived>

template<typename KeyFunc>

auto helios::utils::FunctionalAdapterBase< Derived >::GroupBy ( const KeyFunc & key_func ) const

nodiscardconstexpr

Terminal operation: groups elements by a key function.

Template Parameters

KeyFunc Key extraction function type

Parameters

key_func Function to extract grouping key from each element

Returns: Map from keys to vectors of elements with that key

Definition at line 4275 of file functional_adapters.hpp.

◆ GroupByWith()

template<typename Derived>

template<typename KeyFunc, typename MapAllocator, typename ValueAllocator>

auto helios::utils::FunctionalAdapterBase< Derived >::GroupByWith	(	const KeyFunc &	key_func,
		MapAllocator	map_allocator,
		ValueAllocator	value_allocator ) const

nodiscardconstexpr

Terminal operation: groups elements by key with custom allocators.

Template Parameters

KeyFunc	Key extraction function type
MapAllocator	Allocator for unordered_map nodes
ValueAllocator	Allocator for grouped vectors

Parameters

key_func	Function to extract grouping key from each element
map_allocator	Allocator for map storage
value_allocator	Allocator for each grouped vector

Returns: Map from keys to vectors using provided allocators

Definition at line 4296 of file functional_adapters.hpp.

◆ Inspect()

template<typename Derived>

template<typename Func>

auto helios::utils::FunctionalAdapterBase< Derived >::Inspect ( Func inspector ) const

inlinenodiscardconstexprnoexcept

Observes each element without modifying it.

Template Parameters

Func	Inspector function type

Parameters

inspector Function to call on each element

Returns: InspectAdapter for side effects

Definition at line 3684 of file functional_adapters.hpp.

◆ Into()

template<typename Derived>

template<typename OutIt>

void helios::utils::FunctionalAdapterBase< Derived >::Into ( OutIt out ) const

constexpr

Terminal operation: writes all elements into an output iterator.

Consumes the adapter and writes each element to the provided output iterator. This is more efficient than Collect() when you already have a destination container.

Template Parameters

OutIt Output iterator type

Parameters

out	Output iterator to write elements into

std::vector<int> results;
query.Filter([](int x) { return x > 5;
}).Into(std::back_inserter(results));

Definition at line 4367 of file functional_adapters.hpp.

◆ Map()

template<typename Derived>

template<typename Func>

auto helios::utils::FunctionalAdapterBase< Derived >::Map ( Func transform ) const

inlinenodiscardconstexprnoexcept

Transforms each element using the given function.

Template Parameters

Func	Transformation function type

Parameters

transform Function to apply to each element

Returns: MapAdapter that transforms adapted results

Definition at line 3607 of file functional_adapters.hpp.

◆ MaxBy()

template<typename Derived>

template<typename KeyFunc>

auto helios::utils::FunctionalAdapterBase< Derived >::MaxBy ( const KeyFunc & key_func ) const

nodiscardconstexpr

Terminal operation: finds the element with the maximum value according to a key function.

Template Parameters

KeyFunc Key extraction function type

Parameters

key_func Function to extract comparison key from each element

Returns: Optional or pointer to the element with maximum key, based on the iterator type

Definition at line 4172 of file functional_adapters.hpp.

◆ MinBy()

template<typename Derived>

template<typename KeyFunc>

auto helios::utils::FunctionalAdapterBase< Derived >::MinBy ( const KeyFunc & key_func ) const

nodiscardconstexpr

Terminal operation: finds the element with the minimum value according to a key function.

Template Parameters

KeyFunc Key extraction function type

Parameters

key_func Function to extract comparison key from each element

Returns: Optional or pointer to the element with maximum key, based on the iterator type

Definition at line 4223 of file functional_adapters.hpp.

◆ None()

template<typename Derived>

template<typename Pred>

bool helios::utils::FunctionalAdapterBase< Derived >::None ( const Pred & predicate ) const

inlinenodiscardconstexpr

Terminal operation: checks if no elements satisfy a predicate.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to test elements

Returns: True if no elements satisfy the predicate, false otherwise

Definition at line 4013 of file functional_adapters.hpp.

◆ Partition()

template<typename Derived>

template<typename Pred>

auto helios::utils::FunctionalAdapterBase< Derived >::Partition ( const Pred & predicate ) const

nodiscardconstexpr

Terminal operation: partitions elements into two groups based on a predicate.

Template Parameters

Pred	Predicate type

Parameters

predicate Function to test elements

Returns: Pair of vectors: first contains elements satisfying predicate, second contains the rest

Definition at line 4118 of file functional_adapters.hpp.

◆ PartitionWith()

template<typename Derived>
requires std::same_as<typename Allocator::value_type, std::iter_value_t<Derived>>

template<typename Pred, typename Allocator>
requires std::same_as<typename Allocator::value_type, std::iter_value_t<Derived>>

auto helios::utils::FunctionalAdapterBase< Derived >::PartitionWith	(	const Pred &	predicate,
		Allocator	allocator ) const

nodiscardconstexpr

Terminal operation: partitions elements with a custom allocator.

Template Parameters

Pred	Predicate type
Allocator	Allocator for result vectors

Parameters

predicate	Function to test elements
allocator	Allocator to use for both result vectors

Returns: Pair of vectors using the provided allocator

Definition at line 4146 of file functional_adapters.hpp.

◆ Reverse()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Reverse ( ) const

inlinenodiscardconstexprnoexcept

Reverses the order of elements.

Note: Requires bidirectional iterator support

Returns: ReverseAdapter that yields elements in reverse order

Definition at line 3755 of file functional_adapters.hpp.

◆ Skip()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Skip ( size_t count ) const

inlinenodiscardconstexprnoexcept

Skips the first count elements.

Parameters

count Number of elements to skip

Returns: SkipAdapter that skips adapted results

Definition at line 3632 of file functional_adapters.hpp.

◆ SkipWhile()

template<typename Derived>

template<typename Pred>

auto helios::utils::FunctionalAdapterBase< Derived >::SkipWhile ( Pred predicate ) const

inlinenodiscardconstexprnoexcept

Skips elements while a predicate is true.

Template Parameters

Pred	Predicate type for skip-while operation

Parameters

predicate Predicate to determine when to stop skipping

Returns: SkipWhileAdapter that conditionally skips elements

Definition at line 3660 of file functional_adapters.hpp.

◆ Slide()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Slide ( size_t window_size ) const

inlinenodiscardconstexprnoexcept

Creates sliding windows over elements.

Parameters

window_size Size of the sliding window

Returns: SlideAdapter that yields windows of elements

Warning: window_size must be greater than 0

Definition at line 3767 of file functional_adapters.hpp.

◆ StepBy()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::StepBy ( size_t step ) const

inlinenodiscardconstexprnoexcept

Takes every Nth element.

Parameters

step	Step size between elements

Returns: StepByAdapter that skips elements

Definition at line 3697 of file functional_adapters.hpp.

◆ Stride()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Stride ( size_t stride ) const

inlinenodiscardconstexprnoexcept

Takes every Nth element with stride.

Parameters

stride Number of elements to skip between yields

Returns: StrideAdapter that yields every Nth element

Warning: stride must be greater than 0

Definition at line 3781 of file functional_adapters.hpp.

◆ Take()

template<typename Derived>

auto helios::utils::FunctionalAdapterBase< Derived >::Take ( size_t count ) const

inlinenodiscardconstexprnoexcept

Limits the number of elements to at most count.

Parameters

count Maximum number of elements to yield

Returns: TakeAdapter that limits adapted results

Definition at line 3620 of file functional_adapters.hpp.

◆ TakeWhile()

template<typename Derived>

template<typename Pred>

auto helios::utils::FunctionalAdapterBase< Derived >::TakeWhile ( Pred predicate ) const

inlinenodiscardconstexprnoexcept

Takes elements while a predicate is true.

Template Parameters

Pred	Predicate type for take-while operation

Parameters

predicate Predicate to determine when to stop taking

Returns: TakeWhileAdapter that conditionally takes elements

Definition at line 3646 of file functional_adapters.hpp.

◆ Zip() [1/3]

template<typename Derived>

template<typename R>

auto helios::utils::FunctionalAdapterBase< Derived >::Zip ( const R & range ) const

inlinenodiscardconstexprnoexcept

Zips another range with this one.

Template Parameters

R	Other range

Parameters

range The other range to zip with

Returns: ZipAdapter that

Definition at line 3827 of file functional_adapters.hpp.

◆ Zip() [2/3]

template<typename Derived>

template<typename OtherIter>

auto helios::utils::FunctionalAdapterBase< Derived >::Zip	(	OtherIter	begin,
		OtherIter	end ) const

inlinenodiscardconstexprnoexcept

Zips another range with this one.

Template Parameters

OtherIter Iterator type to zip with

Parameters

begin	Begin iterator for the other range
end	End iterator for the other range

Returns: ZipAdapter that yields tuples of corresponding elements

Definition at line 3796 of file functional_adapters.hpp.

◆ Zip() [3/3]

template<typename Derived>

template<typename R>

auto helios::utils::FunctionalAdapterBase< Derived >::Zip ( R & range ) const

inlinenodiscardconstexprnoexcept

Zips another range with this one.

Template Parameters

R	Other range

Parameters

range The other range to zip with

Returns: ZipAdapter that

Definition at line 3813 of file functional_adapters.hpp.

Public Member Functions

Protected Member Functions

Detailed Description

Member Function Documentation

◆ All()

◆ Any()

◆ Chain() [1/3]

◆ Chain() [2/3]

◆ Chain() [3/3]

◆ Collect()

◆ CollectWith() [1/3]

◆ CollectWith() [2/3]

◆ CollectWith() [3/3]

◆ CountIf()

◆ Enumerate()

◆ Filter()

◆ Find()

◆ Fold()

◆ ForEach()

◆ GetDerived() [1/2]

◆ GetDerived() [2/2]

◆ GroupBy()

◆ GroupByWith()

◆ Inspect()

◆ Into()

◆ Map()

◆ MaxBy()

◆ MinBy()

◆ None()

◆ Partition()

◆ PartitionWith()

◆ Reverse()

◆ Skip()

◆ SkipWhile()

◆ Slide()

◆ StepBy()

◆ Stride()

◆ Take()

◆ TakeWhile()

◆ Zip() [1/3]

◆ Zip() [2/3]

◆ Zip() [3/3]