Jug::GroupBy< Iterator, KeyGetter > Class Template Reference

#include <GroupBy.hpp>

Classes
class	GroupIterator
	Iterator type representing a group of elements. More...

Public Types
using	Key = std::decay_t< decltype(KeyGetter()(*Iterator()))>
	The key type that identifies elements within a group. More...
using	Group = std::pair< Key, Range< Iterator > >
	A Group is an iterator range with the associated key. More...
using	GroupEndIterator = Iterator
using	Key = std::decay_t< decltype(KeyGetter()(*Iterator()))>
	The key type that identifies elements within a group. More...
using	Group = std::pair< Key, Range< Iterator > >
	A Group is an iterator range with the associated key. More...
using	GroupEndIterator = Iterator
using	Key = std::decay_t< decltype(KeyGetter()(*Iterator()))>
	The key type that identifies elements within a group. More...
using	Group = std::pair< Key, Range< Iterator > >
	A Group is an iterator range with the associated key. More...
using	GroupEndIterator = Iterator

Public Member Functions
constexpr	GroupBy (Iterator begin, Iterator end, KeyGetter keyGetter=KeyGetter())
	Construct the group-by proxy for an iterator range. More...
constexpr GroupIterator	begin () const
constexpr GroupEndIterator	end () const
constexpr bool	empty () const
constexpr	GroupBy (Iterator begin, Iterator end, KeyGetter keyGetter=KeyGetter())
	Construct the group-by proxy for an iterator range. More...
constexpr GroupIterator	begin () const
constexpr GroupEndIterator	end () const
constexpr bool	empty () const
constexpr	GroupBy (Iterator begin, Iterator end, KeyGetter keyGetter=KeyGetter())
	Construct the group-by proxy for an iterator range. More...
constexpr GroupIterator	begin () const
constexpr GroupEndIterator	end () const
constexpr bool	empty () const

Detailed Description

template<typename Iterator, typename KeyGetter>
class Jug::GroupBy< Iterator, KeyGetter >

Proxy for iterating over groups of elements within a container.

Note

Each group will contain at least one element.

Consecutive elements with the same key (as defined by the KeyGetter) are placed in one group. The proxy should always be used as part of a range-based for loop. In combination with structured bindings to reduce the boilerplate, the group iteration can be written as

for (auto&& [key, elements] : GroupBy<...>(...)) {
    // do something with just the key
    ...

    // iterate over the group elements
    for (const auto& element : elements) {
        ...
    }
}

Member Typedef Documentation

Group [1/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::Group = std::pair<Key, Range<Iterator> >

A Group is an iterator range with the associated key.

Group [2/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::Group = std::pair<Key, Range<Iterator> >

A Group is an iterator range with the associated key.

Group [3/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::Group = std::pair<Key, Range<Iterator> >

A Group is an iterator range with the associated key.

GroupEndIterator [1/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::GroupEndIterator = Iterator

Iterator type representing the end of the groups.

The end iterator will not be dereferenced in C++17 range-based loops. It can thus be a simpler type without the overhead of the full group iterator below.

GroupEndIterator [2/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::GroupEndIterator = Iterator

Iterator type representing the end of the groups.

The end iterator will not be dereferenced in C++17 range-based loops. It can thus be a simpler type without the overhead of the full group iterator below.

GroupEndIterator [3/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::GroupEndIterator = Iterator

Iterator type representing the end of the groups.

The end iterator will not be dereferenced in C++17 range-based loops. It can thus be a simpler type without the overhead of the full group iterator below.

Key [1/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::Key = std::decay_t<decltype(KeyGetter()(*Iterator()))>

The key type that identifies elements within a group.

Key [2/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::Key = std::decay_t<decltype(KeyGetter()(*Iterator()))>

The key type that identifies elements within a group.

Key [3/3]

template<typename Iterator , typename KeyGetter >

using Jug::GroupBy< Iterator, KeyGetter >::Key = std::decay_t<decltype(KeyGetter()(*Iterator()))>

The key type that identifies elements within a group.

Constructor & Destructor Documentation

GroupBy() [1/3]

template<typename Iterator , typename KeyGetter >

constexpr Jug::GroupBy< Iterator, KeyGetter >::GroupBy ( Iterator  begin, Iterator  end, KeyGetter  keyGetter = KeyGetter()  )

inlineconstexpr

Construct the group-by proxy for an iterator range.

GroupBy() [2/3]

template<typename Iterator , typename KeyGetter >

constexpr Jug::GroupBy< Iterator, KeyGetter >::GroupBy ( Iterator  begin, Iterator  end, KeyGetter  keyGetter = KeyGetter()  )

inlineconstexpr

Construct the group-by proxy for an iterator range.

GroupBy() [3/3]

template<typename Iterator , typename KeyGetter >

constexpr Jug::GroupBy< Iterator, KeyGetter >::GroupBy ( Iterator  begin, Iterator  end, KeyGetter  keyGetter = KeyGetter()  )

inlineconstexpr

Construct the group-by proxy for an iterator range.

Member Function Documentation

begin() [1/3]

template<typename Iterator , typename KeyGetter >

constexpr GroupIterator Jug::GroupBy< Iterator, KeyGetter >::begin ( ) const

inlineconstexpr

begin() [2/3]

template<typename Iterator , typename KeyGetter >

constexpr GroupIterator Jug::GroupBy< Iterator, KeyGetter >::begin ( ) const

inlineconstexpr

begin() [3/3]

template<typename Iterator , typename KeyGetter >

constexpr GroupIterator Jug::GroupBy< Iterator, KeyGetter >::begin ( ) const

inlineconstexpr

empty() [1/3]

template<typename Iterator , typename KeyGetter >

constexpr bool Jug::GroupBy< Iterator, KeyGetter >::empty ( ) const

inlineconstexpr

empty() [2/3]

template<typename Iterator , typename KeyGetter >

constexpr bool Jug::GroupBy< Iterator, KeyGetter >::empty ( ) const

inlineconstexpr

empty() [3/3]

template<typename Iterator , typename KeyGetter >

constexpr bool Jug::GroupBy< Iterator, KeyGetter >::empty ( ) const

inlineconstexpr

end() [1/3]

template<typename Iterator , typename KeyGetter >

constexpr GroupEndIterator Jug::GroupBy< Iterator, KeyGetter >::end ( ) const

inlineconstexpr

end() [2/3]

template<typename Iterator , typename KeyGetter >

constexpr GroupEndIterator Jug::GroupBy< Iterator, KeyGetter >::end ( ) const

inlineconstexpr

end() [3/3]

template<typename Iterator , typename KeyGetter >

constexpr GroupEndIterator Jug::GroupBy< Iterator, KeyGetter >::end ( ) const

inlineconstexpr

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

• /builds/eic/juggler/JugBase/JugBase/Utilities/GroupBy.hpp