helios::utils::MapAdapter< Iter, Func > Class Template Reference

Iterator adapter that transforms each element using a function. More...

#include <functional_adapters.hpp>

Inheritance diagram for helios::utils::MapAdapter< Iter, Func >:

Public Types
using	iterator_concept = std::input_iterator_tag
using	iterator_category = std::input_iterator_tag
using	value_type = typename DeduceValueType<std::iter_value_t<Iter>>::Type
using	reference = value_type
using	pointer = void
using	difference_type = std::iter_difference_t<Iter>

Public Member Functions
constexpr	MapAdapter (Iter begin, Iter end, Func transform) noexcept(std::is_nothrow_move_constructible_v< Iter > &&std::is_nothrow_move_constructible_v< Func >)
	Constructs a map adapter with the given iterator range and transform function.
template<ExternalRange R> requires MapAdapterRequirements<std::ranges::iterator_t<R>, Func>
constexpr	MapAdapter (R &range, Func transform) noexcept(noexcept(MapAdapter(std::ranges::begin(range), std::ranges::end(range), std::move(transform))))
	Constructs a map adapter from a range and transform function.
template<ExternalRange R> requires MapAdapterRequirements<std::ranges::iterator_t<const R>, Func>
constexpr	MapAdapter (const R &range, Func transform) noexcept(noexcept(MapAdapter(std::ranges::cbegin(range), std::ranges::cend(range), std::move(transform))))
	Constructs a map adapter from a const range and transform function.
constexpr	MapAdapter (const MapAdapter &) noexcept(std::is_nothrow_copy_constructible_v< Iter > &&std::is_nothrow_copy_constructible_v< Func >)=default
constexpr	MapAdapter (MapAdapter &&) noexcept(std::is_nothrow_move_constructible_v< Iter > &&std::is_nothrow_move_constructible_v< Func >)=default
constexpr	~MapAdapter () noexcept(std::is_nothrow_destructible_v< Iter > &&std::is_nothrow_destructible_v< Func >)=default
constexpr MapAdapter &	operator= (const MapAdapter &) noexcept(std::is_nothrow_copy_assignable_v< Iter > &&std::is_nothrow_copy_assignable_v< Func >)=default
constexpr MapAdapter &	operator= (MapAdapter &&) noexcept(std::is_nothrow_move_assignable_v< Iter > &&std::is_nothrow_move_assignable_v< Func >)=default
constexpr MapAdapter &	operator++ () noexcept(noexcept(++std::declval< Iter & >()))
constexpr MapAdapter	operator++ (int) noexcept(std::is_nothrow_copy_constructible_v< MapAdapter > &&noexcept(++std::declval< MapAdapter & >()))
constexpr reference	operator* () const noexcept(std::is_nothrow_invocable_v< Func, std::iter_value_t< Iter > > &&noexcept(*std::declval< const Iter & >()))
pointer	operator-> () const =delete
constexpr bool	operator== (const MapAdapter &other) const noexcept(noexcept(std::declval< const Iter & >()==std::declval< const Iter & >()))
constexpr bool	operator!= (const MapAdapter &other) const noexcept(noexcept(std::declval< const MapAdapter & >()==std::declval< const MapAdapter & >()))
constexpr MapAdapter	begin () const noexcept(std::is_nothrow_copy_constructible_v< MapAdapter >)
constexpr MapAdapter	end () const noexcept(std::is_nothrow_constructible_v< MapAdapter, const Iter &, const Iter &, const Func & >)
Public Member Functions inherited from helios::utils::FunctionalAdapterBase< MapAdapter< Iter, Func > >
constexpr auto	Filter (Pred predicate) const noexcept(noexcept(FilterAdapter< MapAdapter< Iter, Func >, Pred >(GetDerived().begin(), GetDerived().end(), std::move(predicate))))
	Chains another filter operation on top of this iterator.
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< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end(), count)))
	Limits the number of elements to at most count.
constexpr auto	Skip (size_t count) const noexcept(noexcept(SkipAdapter< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end(), count)))
	Skips the first count elements.
constexpr auto	TakeWhile (Pred predicate) const noexcept(noexcept(TakeWhileAdapter< MapAdapter< Iter, Func >, Pred >(GetDerived().begin(), GetDerived().end(), std::move(predicate))))
	Takes elements while a predicate is true.
constexpr auto	SkipWhile (Pred predicate) const noexcept(noexcept(SkipWhileAdapter< MapAdapter< Iter, Func >, Pred >(GetDerived().begin(), GetDerived().end(), std::move(predicate))))
	Skips elements while a predicate is true.
constexpr auto	Enumerate () const noexcept(noexcept(EnumerateAdapter< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end())))
	Adds an index to each element.
constexpr auto	Inspect (Func inspector) const noexcept(noexcept(InspectAdapter< MapAdapter< Iter, Func >, Func >(GetDerived().begin(), GetDerived().end(), std::move(inspector))))
	Observes each element without modifying it.
constexpr auto	StepBy (size_t step) const noexcept(noexcept(StepByAdapter< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end(), step)))
	Takes every Nth element.
constexpr auto	Chain (OtherIter begin, OtherIter end) const noexcept(noexcept(ChainAdapter< MapAdapter< Iter, Func >, OtherIter >(GetDerived().begin(), GetDerived().end(), std::move(begin), std::move(end))))
	Chains another range after this one.
constexpr auto	Reverse () const noexcept(noexcept(ReverseAdapter< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end())))
	Reverses the order of elements.
constexpr auto	Slide (size_t window_size) const noexcept(noexcept(SlideAdapter< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end(), window_size)))
	Creates sliding windows over elements.
constexpr auto	Stride (size_t stride) const noexcept(noexcept(StrideAdapter< MapAdapter< Iter, Func > >(GetDerived().begin(), GetDerived().end(), stride)))
	Takes every Nth element with stride.
constexpr auto	Zip (OtherIter begin, OtherIter end) const noexcept(noexcept(ZipAdapter< MapAdapter< Iter, Func >, OtherIter >(GetDerived().begin(), GetDerived().end(), std::move(begin), std::move(end))))
	Zips another range with this one.
constexpr void	ForEach (const Action &action) const
	Terminal operation: applies an action to each element.
constexpr T	Fold (T init, const Folder &folder) const
	Terminal operation: reduces elements to a single value using a folder function.
constexpr auto	Find (const Pred &predicate) const
	Terminal operation: finds the first element satisfying a predicate.
constexpr size_t	CountIf (const Pred &predicate) const
	Terminal operation: counts elements satisfying a predicate.
constexpr auto	Partition (const Pred &predicate) const
	Terminal operation: partitions elements into two groups based on a predicate.
constexpr auto	PartitionWith (const Pred &predicate, Allocator allocator) const
	Terminal operation: partitions elements with a custom allocator.
constexpr auto	MaxBy (const KeyFunc &key_func) const
	Terminal operation: finds the element with the maximum value according to a key function.
constexpr auto	MinBy (const KeyFunc &key_func) const
	Terminal operation: finds the element with the minimum value according to a key function.
constexpr auto	GroupBy (const KeyFunc &key_func) const
	Terminal operation: groups elements by a key function.
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.
constexpr auto	CollectWith (Allocator allocator={}) const
	Terminal operation: collects all elements into a vector with a custom allocator.
constexpr void	Into (OutIt out) const
	Terminal operation: writes all elements into an output iterator.
constexpr bool	Any (const Pred &predicate) const
	Terminal operation: checks if any element satisfies a predicate.
constexpr bool	All (const Pred &predicate) const
	Terminal operation: checks if all elements satisfy a predicate.
constexpr bool	None (const Pred &predicate) const
	Terminal operation: checks if no elements satisfy a predicate.

Additional Inherited Members
Protected Member Functions inherited from helios::utils::FunctionalAdapterBase< MapAdapter< Iter, Func > >
constexpr MapAdapter< Iter, Func > &	GetDerived () noexcept
	Gets reference to derived class instance.

Detailed Description

template<typename Iter, typename Func>
requires MapAdapterRequirements<Iter, Func>
class helios::utils::MapAdapter< Iter, Func >

Iterator adapter that transforms each element using a function.

This adapter applies a transformation function to each element during iteration. The transformation is lazy - it happens when the element is accessed, not when the adapter is created.

The transformation function can accept either the full value or individual tuple components if the value is a tuple type.

Note

This adapter maintains forward iterator semantics. The adapter is constexpr-compatible for compile-time evaluation.

Template Parameters

Iter	Underlying iterator type that satisfies IteratorLike concept
Func	Transformation function type

auto positions = query.Map([](const Transform& t) {
  return t.position;
});

Definition at line 676 of file functional_adapters.hpp.

Member Typedef Documentation

difference_type

template<typename Iter, typename Func>

using helios::utils::MapAdapter< Iter, Func >::difference_type = std::iter_difference_t<Iter>

Definition at line 699 of file functional_adapters.hpp.

iterator_category

template<typename Iter, typename Func>

using helios::utils::MapAdapter< Iter, Func >::iterator_category = std::input_iterator_tag

Definition at line 695 of file functional_adapters.hpp.

iterator_concept

template<typename Iter, typename Func>

using helios::utils::MapAdapter< Iter, Func >::iterator_concept = std::input_iterator_tag

Definition at line 694 of file functional_adapters.hpp.

pointer

template<typename Iter, typename Func>

using helios::utils::MapAdapter< Iter, Func >::pointer = void

Definition at line 698 of file functional_adapters.hpp.

reference

template<typename Iter, typename Func>

using helios::utils::MapAdapter< Iter, Func >::reference = value_type

Definition at line 697 of file functional_adapters.hpp.

value_type

template<typename Iter, typename Func>

using helios::utils::MapAdapter< Iter, Func >::value_type = typename DeduceValueType<std::iter_value_t<Iter>>::Type

Definition at line 696 of file functional_adapters.hpp.

Constructor & Destructor Documentation

MapAdapter() [1/5]

template<typename Iter, typename Func>

helios::utils::MapAdapter< Iter, Func >::MapAdapter ( Iter begin, Iter end, Func transform )

inlineconstexprnoexcept

Constructs a map adapter with the given iterator range and transform function.

Parameters

begin	Start of the iterator range
end	End of the iterator range
transform	Function to transform elements

Definition at line 708 of file functional_adapters.hpp.

MapAdapter() [2/5]

template<typename Iter, typename Func>

template<ExternalRange R>
requires MapAdapterRequirements<std::ranges::iterator_t<R>, Func>

helios::utils::MapAdapter< Iter, Func >::MapAdapter ( R & range, Func transform )

inlineconstexprnoexcept

Constructs a map adapter from a range and transform function.

Template Parameters

R	The type of the input range

Parameters

range	The input range to adapt
transform	Function to transform elements

Definition at line 724 of file functional_adapters.hpp.

MapAdapter() [3/5]

template<typename Iter, typename Func>

template<ExternalRange R>
requires MapAdapterRequirements<std::ranges::iterator_t<const R>, Func>

helios::utils::MapAdapter< Iter, Func >::MapAdapter ( const R & range, Func transform )

inlineconstexprnoexcept

Constructs a map adapter from a const range and transform function.

Template Parameters

R	The type of the input range

Parameters

range	The input range to adapt
transform	Function to transform elements

Definition at line 738 of file functional_adapters.hpp.

MapAdapter() [4/5]

template<typename Iter, typename Func>

helios::utils::MapAdapter< Iter, Func >::MapAdapter ( const MapAdapter< Iter, Func > & ) const &&

constexprdefaultnoexcept

MapAdapter() [5/5]

template<typename Iter, typename Func>

helios::utils::MapAdapter< Iter, Func >::MapAdapter ( MapAdapter< Iter, Func > && ) const &&

constexprdefaultnoexcept

~MapAdapter()

template<typename Iter, typename Func>

helios::utils::MapAdapter< Iter, Func >::~MapAdapter ( ) &&

constexprdefaultnoexcept

Member Function Documentation

begin()

template<typename Iter, typename Func>

MapAdapter helios::utils::MapAdapter< Iter, Func >::begin ( ) const

inlinenodiscardconstexprnoexcept

Definition at line 784 of file functional_adapters.hpp.

end()

template<typename Iter, typename Func>

MapAdapter helios::utils::MapAdapter< Iter, Func >::end ( ) const

inlinenodiscardconstexprnoexcept

Definition at line 789 of file functional_adapters.hpp.

operator!=()

template<typename Iter, typename Func>

bool helios::utils::MapAdapter< Iter, Func >::operator!= ( const MapAdapter< Iter, Func > & other ) const

inlinenodiscardconstexprnoexcept

Definition at line 778 of file functional_adapters.hpp.

operator*()

template<typename Iter, typename Func>
requires MapAdapterRequirements<Iter, Func>

auto helios::utils::MapAdapter< Iter, Func >::operator* ( ) const

nodiscardconstexprnoexcept

Definition at line 829 of file functional_adapters.hpp.

operator++() [1/2]

template<typename Iter, typename Func>
requires MapAdapterRequirements<Iter, Func>

auto helios::utils::MapAdapter< Iter, Func >::operator++ ( )

constexprnoexcept

Definition at line 811 of file functional_adapters.hpp.

operator++() [2/2]

template<typename Iter, typename Func>
requires MapAdapterRequirements<Iter, Func>

auto helios::utils::MapAdapter< Iter, Func >::operator++ ( int )

nodiscardconstexprnoexcept

Definition at line 819 of file functional_adapters.hpp.

operator->()

template<typename Iter, typename Func>

pointer helios::utils::MapAdapter< Iter, Func >::operator-> ( ) const

delete

operator=() [1/2]

template<typename Iter, typename Func>

MapAdapter & helios::utils::MapAdapter< Iter, Func >::operator= ( const MapAdapter< Iter, Func > & ) &&

constexprdefaultnoexcept

operator=() [2/2]

template<typename Iter, typename Func>

MapAdapter & helios::utils::MapAdapter< Iter, Func >::operator= ( MapAdapter< Iter, Func > && ) &&

constexprdefaultnoexcept

operator==()

template<typename Iter, typename Func>

bool helios::utils::MapAdapter< Iter, Func >::operator== ( const MapAdapter< Iter, Func > & other ) const

inlinenodiscardconstexprnoexcept

Definition at line 773 of file functional_adapters.hpp.