A forwarder class for std::array. More...

#include <common/ArrayForwarder.h>

Public Types
typedef _Tp	value_type

typedef value_type *	pointer

typedef const value_type *	const_pointer

typedef value_type &	reference

typedef const value_type &	const_reference

typedef value_type *	iterator

typedef const value_type *	const_iterator

typedef std::size_t	size_type

typedef std::ptrdiff_t	difference_type

typedef std::reverse_iterator< iterator >	reverse_iterator

typedef std::reverse_iterator< const_iterator >	const_reverse_iterator

Public Member Functions
	ArrayForwarder ()=default

	ArrayForwarder (std::array< _Tp, _Nm > arr)

void	fill (const value_type &__u)

void	swap (ArrayForwarder &__other) noexcept(noexcept(std::swap(std::declval< _Tp &>(), std::declval< _Tp &>())))

_GLIBCXX17_CONSTEXPR iterator	begin () noexcept

_GLIBCXX17_CONSTEXPR const_iterator	begin () const noexcept

_GLIBCXX17_CONSTEXPR iterator	end () noexcept

_GLIBCXX17_CONSTEXPR const_iterator	end () const noexcept

_GLIBCXX17_CONSTEXPR reverse_iterator	rbegin () noexcept

_GLIBCXX17_CONSTEXPR const_reverse_iterator	rbegin () const noexcept

_GLIBCXX17_CONSTEXPR reverse_iterator	rend () noexcept

_GLIBCXX17_CONSTEXPR const_reverse_iterator	rend () const noexcept

_GLIBCXX17_CONSTEXPR const_iterator	cbegin () const noexcept

_GLIBCXX17_CONSTEXPR const_iterator	cend () const noexcept

_GLIBCXX17_CONSTEXPR const_reverse_iterator	crbegin () const noexcept

_GLIBCXX17_CONSTEXPR const_reverse_iterator	crend () const noexcept

constexpr size_type	size () const noexcept

constexpr size_type	max_size () const noexcept

constexpr bool	empty () const noexcept

_GLIBCXX17_CONSTEXPR reference	operator[] (size_type __n) noexcept

constexpr const_reference	operator[] (size_type __n) const noexcept

_GLIBCXX17_CONSTEXPR reference	at (size_type __n)

constexpr const_reference	at (size_type __n) const

_GLIBCXX17_CONSTEXPR reference	front () noexcept

constexpr const_reference	front () const noexcept

_GLIBCXX17_CONSTEXPR reference	back () noexcept

constexpr const_reference	back () const noexcept

_GLIBCXX17_CONSTEXPR pointer	data () noexcept

_GLIBCXX17_CONSTEXPR const_pointer	data () const noexcept

Private Attributes
std::array< _Tp, _Nm >	_content

Friends
bool	operator== (const ArrayForwarder< _Tp, _Nm > &, const ArrayForwarder< _Tp, _Nm > &)

bool	operator!= (const ArrayForwarder< _Tp, _Nm > &__one, const ArrayForwarder< _Tp, _Nm > &__two)

bool	operator< (const ArrayForwarder< _Tp, _Nm > &__a, const ArrayForwarder< _Tp, _Nm > &__b)

bool	operator> (const ArrayForwarder< _Tp, _Nm > &__one, const ArrayForwarder< _Tp, _Nm > &__two)

bool	operator<= (const ArrayForwarder< _Tp, _Nm > &__one, const ArrayForwarder< _Tp, _Nm > &__two)

bool	operator>= (const ArrayForwarder< _Tp, _Nm > &__one, const ArrayForwarder< _Tp, _Nm > &__two)

Detailed Description

template<typename _Tp, std::size_t _Nm>
class Herd::ArrayForwarder< _Tp, _Nm >

A forwarder class for std::array.

std::array persistence in Root is treated in a way that makes classes deriving from it unsuitable for automatic dictionary generation, due to rootcling not generating the dictionary for the std::array base class. More information are available on the Root forum and bug tracker:

https://root-forum.cern.ch/t/cant-generate-dictionary-for-std-array-containing-a-custom-class/32592 https://sft.its.cern.ch/jira/browse/ROOT-9943

Until a proper fix is implemented in Root, the workaround is to define a class that implements the interface of std::array by forwarding all the calls to a private std::array member, and inherit from this forwarder class. In this way std::array is no longer a base class and there's no need to generate a dictionary for it, making rootcling happy again.

The declaration of ArrayForwarder is adapted from a copy-paste of std::array shipped with gcc 8.2.1.