778 lines
24 KiB
C++
778 lines
24 KiB
C++
/*
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
*
|
|
* Copyright 2010-2018 Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "types/traits.hpp"
|
|
#include "tuple/value.hpp"
|
|
#include "variadic.hpp"
|
|
#include "view.hpp"
|
|
|
|
#include <iterator>
|
|
|
|
template <typename Base>
|
|
class referencing_iterator {
|
|
protected:
|
|
typedef typename std::enable_if<
|
|
is_dereferencable<
|
|
typename Base::value_type
|
|
>::value,
|
|
typename Base::value_type
|
|
>::type base_value_type;
|
|
|
|
public:
|
|
typedef typename dereferenced_type<base_value_type>::type value_type ;
|
|
typedef typename Base::difference_type difference_type ;
|
|
typedef value_type& reference ;
|
|
typedef value_type* pointer;
|
|
typedef typename Base::iterator_category iterator_category;
|
|
|
|
protected:
|
|
Base m_base;
|
|
|
|
public:
|
|
explicit referencing_iterator (Base _base):
|
|
m_base (_base)
|
|
{ ; }
|
|
|
|
referencing_iterator& operator++() { ++m_base; return *this; }
|
|
referencing_iterator operator++(int) { auto val = *this; ++m_base; return val; }
|
|
|
|
bool operator== (const referencing_iterator<Base> &rhs) { return m_base == rhs.m_base; }
|
|
bool operator!= (const referencing_iterator<Base> &rhs) { return m_base != rhs.m_base; }
|
|
bool operator>= (const referencing_iterator<Base> &rhs) { return m_base >= rhs.m_base; }
|
|
bool operator<= (const referencing_iterator<Base> &rhs) { return m_base <= rhs.m_base; }
|
|
bool operator> (const referencing_iterator<Base> &rhs) { return m_base > rhs.m_base; }
|
|
bool operator< (const referencing_iterator<Base> &rhs) { return m_base < rhs.m_base; }
|
|
|
|
const value_type& operator*() const
|
|
{ return **m_base; }
|
|
reference operator*()
|
|
{ return **m_base; }
|
|
|
|
difference_type operator-(const referencing_iterator<Base>& rhs) const { return m_base - rhs.m_base; }
|
|
referencing_iterator<Base> operator-(int rhs) const { return referencing_iterator (m_base - rhs); }
|
|
referencing_iterator<Base> operator+(int rhs) const { return referencing_iterator (m_base + rhs); }
|
|
|
|
};
|
|
|
|
|
|
namespace cruft {
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// an output iterator that inserts a delimiter between successive
|
|
/// assignments
|
|
///
|
|
/// very useful for outputting comma seperated lists to an ostream, eg:
|
|
///
|
|
/// std::copy (
|
|
/// std::cbegin (container),
|
|
/// std::cend (container),
|
|
/// cruft::infix_iterator<value_type> (os, ", ")
|
|
/// );
|
|
template <
|
|
typename T,
|
|
class CharT = char,
|
|
class Traits = std::char_traits<CharT>
|
|
>
|
|
class infix_iterator : public std::iterator<std::output_iterator_tag, void, void, void, void> {
|
|
public:
|
|
using char_type = CharT;
|
|
using traits_type = Traits;
|
|
using ostream_type = std::basic_ostream<char_type, traits_type>;
|
|
|
|
infix_iterator (ostream_type& _output, const CharT *_delimiter):
|
|
m_output (_output),
|
|
m_delimiter (_delimiter)
|
|
{ ; }
|
|
|
|
infix_iterator&
|
|
operator= (T const &value)
|
|
{
|
|
if (!m_first)
|
|
m_output << m_delimiter;
|
|
|
|
m_output << value;
|
|
m_first = false;
|
|
|
|
return *this;
|
|
}
|
|
|
|
infix_iterator& operator* (void) { return *this; }
|
|
infix_iterator& operator++ (void) { return *this; }
|
|
infix_iterator& operator++ (int) { return *this; }
|
|
|
|
private:
|
|
bool m_first = true;
|
|
ostream_type &m_output;
|
|
const CharT *m_delimiter;
|
|
};
|
|
|
|
|
|
namespace detail {
|
|
template <typename ContainerT, typename CharT>
|
|
struct infix_t {
|
|
const ContainerT &_container;
|
|
const CharT *_delimiter;
|
|
};
|
|
|
|
template <typename ContainerT, typename CharT>
|
|
std::ostream&
|
|
operator<< (std::ostream &os, const infix_t<ContainerT,CharT> &val)
|
|
{
|
|
std::copy (std::cbegin (val._container),
|
|
std::cend (val._container),
|
|
infix_iterator<typename ContainerT::value_type> (os, val._delimiter));
|
|
return os;
|
|
}
|
|
|
|
};
|
|
|
|
|
|
/// a helper function that returns an object that will use a
|
|
/// cruft::infix_iterator to output a container's values to an ostream with
|
|
/// the given delimiter.
|
|
///
|
|
/// reduces boilerplate code required to output lists of things
|
|
///
|
|
/// std::cout << cruft::make_infix (container) << '\n';
|
|
template <typename ContainerT, typename CharT = char>
|
|
auto
|
|
make_infix (const ContainerT &_container, const CharT *_delimiter = ", ")
|
|
{
|
|
return detail::infix_t<ContainerT,CharT> { _container, _delimiter };
|
|
}
|
|
|
|
|
|
template <typename ValueT, size_t CountV>
|
|
auto
|
|
make_infix (const ValueT (&val)[CountV])
|
|
{
|
|
return make_infix (cruft::view {val});
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
//
|
|
template <typename IteratorT>
|
|
struct numeric_iterator : public std::iterator<
|
|
typename std::iterator_traits<IteratorT>::iterator_category,
|
|
decltype (+std::declval<typename std::iterator_traits<IteratorT>::value_type> ()),
|
|
typename std::iterator_traits<IteratorT>::difference_type,
|
|
typename std::iterator_traits<IteratorT>::pointer,
|
|
typename std::iterator_traits<IteratorT>::reference
|
|
> {
|
|
static_assert (std::is_arithmetic_v<typename std::iterator_traits<numeric_iterator>::value_type>);
|
|
|
|
explicit numeric_iterator (IteratorT _inner):
|
|
m_inner (_inner)
|
|
{ ; }
|
|
|
|
auto operator++ (void) { ++m_inner; return *this; }
|
|
|
|
auto
|
|
operator- (const numeric_iterator &rhs) const
|
|
{
|
|
return typename std::iterator_traits<IteratorT>::difference_type { m_inner - rhs.m_inner };
|
|
}
|
|
|
|
auto
|
|
operator* (void) const
|
|
{
|
|
return +*m_inner;
|
|
}
|
|
|
|
auto operator== (const numeric_iterator &rhs) const { return m_inner == rhs.m_inner; }
|
|
auto operator!= (const numeric_iterator &rhs) const { return m_inner != rhs.m_inner; }
|
|
|
|
private:
|
|
IteratorT m_inner;
|
|
};
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
// convenience function that constructs a view of numeric_iterators for a
|
|
// provided container
|
|
template <typename ContainerT>
|
|
auto
|
|
numeric_view (ContainerT &data)
|
|
{
|
|
return cruft::view {
|
|
numeric_iterator (std::begin (data)),
|
|
numeric_iterator (std::end (data))
|
|
};
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename ContainerT>
|
|
auto
|
|
numeric_view (const ContainerT &data)
|
|
{
|
|
return cruft::view {
|
|
numeric_iterator (std::begin (data)),
|
|
numeric_iterator (std::end (data))
|
|
};
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename ValueT = std::size_t>
|
|
class iota {
|
|
public:
|
|
using value_type = ValueT;
|
|
|
|
iota (ValueT _total)
|
|
: m_total (_total)
|
|
{ ; }
|
|
|
|
struct iterator {
|
|
iterator (ValueT _value)
|
|
: m_value (_value)
|
|
{ ; }
|
|
|
|
ValueT const* operator-> () const noexcept { return &m_value; }
|
|
ValueT const& operator* () const noexcept { return m_value; }
|
|
|
|
iterator& operator++ () noexcept { ++m_value; return *this; }
|
|
|
|
bool operator!= (iterator const &rhs) const noexcept { return m_value != rhs.m_value; }
|
|
|
|
ValueT m_value;
|
|
};
|
|
|
|
iterator begin (void) const { return iterator( 0); }
|
|
iterator end (void) const { return iterator(m_total); }
|
|
ValueT size (void) const { return m_total; }
|
|
|
|
private:
|
|
ValueT m_total;
|
|
};
|
|
|
|
|
|
template <typename ValueT>
|
|
iota (ValueT) -> iota<ValueT>;
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename ContainerT>
|
|
class indices {
|
|
public:
|
|
using value_type = std::size_t;
|
|
|
|
indices (const ContainerT &_container):
|
|
m_container (_container)
|
|
{ ; }
|
|
|
|
class iterator {
|
|
public:
|
|
using iterator_category = std::forward_iterator_tag;
|
|
|
|
iterator (value_type _index):
|
|
m_index (_index)
|
|
{ ; }
|
|
|
|
bool
|
|
operator!= (const iterator &rhs) const
|
|
{
|
|
return m_index != rhs.m_index;
|
|
}
|
|
|
|
bool
|
|
operator== (const iterator &rhs) const
|
|
{
|
|
return m_index == rhs.m_index;
|
|
}
|
|
|
|
iterator&
|
|
operator++ (void) &
|
|
{
|
|
++m_index;
|
|
return *this;
|
|
};
|
|
|
|
const value_type&
|
|
operator* (void) const&
|
|
{
|
|
return m_index;
|
|
}
|
|
|
|
private:
|
|
value_type m_index;
|
|
};
|
|
|
|
iterator begin (void) const { return iterator { value_type {0} }; }
|
|
iterator end (void) const { return iterator { m_container.size () }; }
|
|
|
|
constexpr auto size (void) const noexcept
|
|
{
|
|
return std::size (m_container);
|
|
}
|
|
|
|
private:
|
|
const ContainerT &m_container;
|
|
};
|
|
|
|
|
|
template <typename ContainerT>
|
|
indices (ContainerT const&) -> indices<ContainerT>;
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
namespace detail::zip {
|
|
/// A container that holds multiple iterators and returns a tuple of
|
|
/// their results when dereferenced.
|
|
///
|
|
/// \tparam IteratorT A tuple-like object that contains iterators
|
|
template <
|
|
typename IteratorT,
|
|
typename = std::make_index_sequence<std::tuple_size_v<IteratorT>>
|
|
>
|
|
struct iterator;
|
|
|
|
|
|
template <typename IteratorT, std::size_t ...Indices>
|
|
struct iterator<IteratorT, std::index_sequence<Indices...>> {
|
|
public:
|
|
// We can't declare ourselves as a forward_iterator because we're
|
|
// unable to supply references to our value_type when we get
|
|
// dereferenced unless we store the supplied values/references
|
|
// inside ourself.
|
|
//
|
|
// This complicates implementation too much given we have no
|
|
// pressing need for this functionality.
|
|
using iterator_category = std::input_iterator_tag;
|
|
using difference_type = std::ptrdiff_t;
|
|
|
|
iterator (IteratorT _iterators):
|
|
m_iterators (_iterators)
|
|
{ ; }
|
|
|
|
|
|
iterator&
|
|
operator++ (void)
|
|
{
|
|
(++std::get<Indices> (m_iterators), ...);
|
|
return *this;
|
|
}
|
|
|
|
|
|
iterator operator++ (int);
|
|
|
|
|
|
auto
|
|
operator* (void)
|
|
{
|
|
// We deliberately construct a tuple manually here to reduce
|
|
// the risk of dangling references. `forward_as_tuple` and
|
|
// `make_tuple` have resulted in references to locals in the
|
|
// past.
|
|
return std::tuple<
|
|
decltype(*std::get<Indices> (m_iterators))...
|
|
> (
|
|
*std::get<Indices> (m_iterators)...
|
|
);
|
|
}
|
|
|
|
|
|
bool
|
|
operator== (const iterator &rhs) const
|
|
{
|
|
return m_iterators == rhs.m_iterators;
|
|
}
|
|
|
|
|
|
bool
|
|
operator!= (const iterator &rhs) const
|
|
{
|
|
return !(*this == rhs);
|
|
}
|
|
|
|
|
|
private:
|
|
IteratorT m_iterators;
|
|
};
|
|
|
|
|
|
/// A simple container for multiple collections that returns a
|
|
/// wrapped multi-iterator for begin and end.
|
|
///
|
|
/// It is up to the user to ensure StoreT does not contain dangling
|
|
/// references.
|
|
///
|
|
/// \tparam StoreT A tuple-like object of collections (or references
|
|
/// to collections).
|
|
template <typename ...StoreT>
|
|
class collection {
|
|
public:
|
|
collection (StoreT&&... _store):
|
|
m_store (std::forward<StoreT> (_store)...)
|
|
{ ; }
|
|
|
|
|
|
using indices_t = std::make_index_sequence<sizeof...(StoreT)>;
|
|
using begin_t = std::tuple<decltype(std::begin (std::declval<StoreT> ()))...>;
|
|
using end_t = std::tuple<decltype(std::end (std::declval<StoreT> ()))...>;
|
|
|
|
|
|
auto begin (void)&
|
|
{
|
|
return iterator<begin_t, indices_t> (
|
|
tuple::value::map (
|
|
[] (auto &i) noexcept { return std::begin (i); },
|
|
m_store
|
|
)
|
|
);
|
|
}
|
|
|
|
|
|
auto end (void)&
|
|
{
|
|
return iterator<end_t, indices_t> (
|
|
tuple::value::map (
|
|
[] (auto &i) noexcept { return std::end (i); },
|
|
m_store
|
|
)
|
|
);
|
|
}
|
|
|
|
|
|
private:
|
|
std::tuple<StoreT...> m_store;
|
|
};
|
|
}
|
|
|
|
|
|
///------------------------------------------------------------------------
|
|
/// Takes a variable number of container arguments and returns an interable
|
|
/// object with a value_type that is a tuple of the each container's
|
|
/// value_type.
|
|
///
|
|
/// The returned iterator value_type is suitable for using in range-for
|
|
/// and structured bindings (and really, that's the entire point here).
|
|
///
|
|
/// eg, cruft::zip ({1,2,3}, {4,5,6}) ~= {{1,4},{2,5},{3,6}}
|
|
template <typename ...ContainerT>
|
|
auto
|
|
zip (ContainerT&&... data)
|
|
{
|
|
CHECK (((std::size (data) == std::size (variadic::get<0> (data...))) && ...));
|
|
|
|
return detail::zip::collection<ContainerT...> (
|
|
std::forward<ContainerT> (data)...
|
|
);
|
|
}
|
|
|
|
|
|
///------------------------------------------------------------------------
|
|
/// Takes a variable number of containers and returns a zipped iterable
|
|
/// object where the first of the iterator's value_types is the index of
|
|
/// that iterator. ie, It combines container offsets with value_types.
|
|
///
|
|
/// eg, cruft::izip ("abc") ~= {{0,'a'},{1,'b'},{2,'c'}}
|
|
template <typename ...ContainerT>
|
|
auto
|
|
izip (ContainerT&&... data)
|
|
{
|
|
indices idx (::cruft::variadic::get<0> (data...));
|
|
|
|
return zip (
|
|
std::move (idx),
|
|
std::forward<ContainerT> (data)...
|
|
);
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// an output iterator that always discards any parameters on assignment.
|
|
///
|
|
/// sometimes useful to pass to algorithms that generate useful results as
|
|
/// a return value, while not caring about the implicit OutputIterator
|
|
/// results.
|
|
struct discard_iterator : public std::iterator<std::output_iterator_tag, discard_iterator> {
|
|
template <typename T>
|
|
void operator= (const T&) { ; }
|
|
|
|
discard_iterator& operator++ ( ) { return *this; }
|
|
discard_iterator operator++ (int) { return *this; }
|
|
discard_iterator& operator* ( ) { return *this; }
|
|
};
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// an iterator that can be infinitely incremented but never assigned.
|
|
///
|
|
/// useful for iterator ranges where the begin iterator is an output
|
|
/// iterator and hence never reaches an end point (and where we don't want
|
|
/// to engineer the client code to account for this).
|
|
template <
|
|
typename ValueT,
|
|
typename CategoryT,
|
|
typename DistanceT,
|
|
typename PointerT,
|
|
typename ReferenceT
|
|
>
|
|
struct unequal_iterator {
|
|
using value_type = ValueT;
|
|
using iterator_category = CategoryT;
|
|
using difference_type = DistanceT;
|
|
using pointer = PointerT;
|
|
using reference = ReferenceT;
|
|
|
|
unequal_iterator& operator++ ( ) { return *this; }
|
|
unequal_iterator operator++ (int) { return *this; }
|
|
};
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename ContainerT>
|
|
auto
|
|
make_unequal_iterator (const ContainerT&)
|
|
{
|
|
using t = typename std::iterator_traits<typename ContainerT::iterator>;
|
|
|
|
return unequal_iterator<
|
|
typename t::value_type,
|
|
typename t::iterator_category,
|
|
typename t::difference_type,
|
|
typename t::pointer,
|
|
typename t::reference
|
|
> {};
|
|
};
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <
|
|
typename OtherT,
|
|
|
|
typename ValueT,
|
|
typename CategoryT,
|
|
typename DistanceT,
|
|
typename PointerT,
|
|
typename ReferenceT>
|
|
constexpr bool
|
|
operator== (
|
|
const unequal_iterator<ValueT,CategoryT,DistanceT,PointerT,ReferenceT>&,
|
|
const OtherT&
|
|
) {
|
|
return false;
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <
|
|
typename OtherT,
|
|
|
|
typename ValueT,
|
|
typename CategoryT,
|
|
typename DistanceT,
|
|
typename PointerT,
|
|
typename ReferenceT>
|
|
constexpr bool
|
|
operator== (
|
|
const OtherT&,
|
|
const unequal_iterator<ValueT,CategoryT,DistanceT,PointerT,ReferenceT>&
|
|
) {
|
|
return false;
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename OutputIt, typename FunctionT>
|
|
OutputIt
|
|
_transform_by_block (
|
|
const cruft::view<OutputIt> &,
|
|
OutputIt cursor,
|
|
FunctionT &&
|
|
) {
|
|
return cursor;
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename OutputIt, typename FunctionT, typename InputT, typename ...TailT>
|
|
OutputIt
|
|
_transform_by_block (
|
|
const cruft::view<OutputIt> &dst,
|
|
OutputIt cursor,
|
|
FunctionT &&func,
|
|
const InputT &_src,
|
|
TailT &&...tail
|
|
) {
|
|
auto remain = _src;
|
|
if (cursor != dst.begin ()) {
|
|
auto infill = std::distance (cursor, dst.end ());
|
|
if (remain.size () < static_cast<size_t> (infill)) {
|
|
return _transform_by_block (
|
|
dst,
|
|
std::copy_n (remain.begin (), remain.size (), cursor),
|
|
std::forward<FunctionT> (func),
|
|
std::forward<TailT> (tail)...
|
|
);
|
|
}
|
|
|
|
std::copy_n (remain.begin (), infill, cursor);
|
|
func (dst);
|
|
cursor = dst.begin ();
|
|
remain = { remain.begin () + infill, remain.end () };
|
|
}
|
|
|
|
while (remain.size () >= dst.size ()) {
|
|
std::copy_n (remain.begin (), dst.size (), dst.begin ());
|
|
func (dst);
|
|
remain = { remain.begin () + dst.size (), remain.end () };
|
|
}
|
|
|
|
return _transform_by_block (
|
|
dst,
|
|
std::copy (remain.begin (), remain.end (), cursor),
|
|
std::forward<FunctionT> (func),
|
|
std::forward<TailT> (tail)...
|
|
);
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename OutputIt, typename FunctionT, typename ...Args>
|
|
OutputIt
|
|
transform_by_block (const cruft::view<OutputIt> &dst, FunctionT &&func, Args &&...src)
|
|
{
|
|
return _transform_by_block (
|
|
dst,
|
|
dst.begin (),
|
|
std::forward<FunctionT> (func),
|
|
std::forward<Args> (src)...
|
|
);
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// Counts the number of times the iterator is assigned to.
|
|
struct counting_output_iterator {
|
|
// An internal proxy value which is returned when the iterator is
|
|
// dereferenced. It increments the assignment value in the host
|
|
// iterator.
|
|
//
|
|
// The internals of this object are not a stable interface.
|
|
struct assignable {
|
|
assignable (std::size_t &_count)
|
|
: m_count (_count)
|
|
{ ; }
|
|
|
|
template <typename Arg>
|
|
void
|
|
operator= (Arg&&)
|
|
{
|
|
++m_count;
|
|
}
|
|
|
|
private:
|
|
std::size_t &m_count;
|
|
};
|
|
|
|
using value_type = assignable;
|
|
using iterator_category = std::output_iterator_tag;
|
|
using reference = assignable&;
|
|
|
|
counting_output_iterator& operator++ () { return *this; }
|
|
assignable operator* () { return assignable (m_count); }
|
|
|
|
/// Returns the number of times the iterator has been assigned to.
|
|
auto count (void) const { return m_count; }
|
|
|
|
private:
|
|
std::size_t m_count = 0;
|
|
};
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// Adapts a supplied iterator by dereferencing any operations that deal
|
|
/// with the underlying value_type of the supplied iterator.
|
|
template <typename IteratorT>
|
|
struct dereference_adapter {
|
|
//---------------------------------------------------------------------
|
|
using difference_type = typename std::iterator_traits<IteratorT>::difference_type;
|
|
using iterator_category = typename std::iterator_traits<IteratorT>::iterator_category;
|
|
|
|
using value_type = std::remove_reference_t<
|
|
decltype(
|
|
*std::declval<
|
|
typename std::iterator_traits<IteratorT>::value_type
|
|
> ()
|
|
)
|
|
>;
|
|
|
|
using pointer = value_type*;
|
|
using reference = value_type&;
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
dereference_adapter (IteratorT _cursor)
|
|
: m_cursor (_cursor)
|
|
{ ; }
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
// Trivial conditional operations
|
|
decltype(auto)
|
|
operator== (dereference_adapter const &rhs) const
|
|
{
|
|
return m_cursor == rhs.m_cursor;
|
|
}
|
|
|
|
|
|
decltype(auto)
|
|
operator!= (dereference_adapter const &rhs) const
|
|
{
|
|
return !(*this == rhs);
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
// Iterator movement operations
|
|
dereference_adapter&
|
|
operator++ ()
|
|
{
|
|
++m_cursor;
|
|
return *this;
|
|
}
|
|
|
|
|
|
difference_type
|
|
operator- (dereference_adapter const &rhs) const
|
|
{
|
|
return m_cursor - rhs.m_cursor;
|
|
}
|
|
|
|
|
|
auto
|
|
operator+ (difference_type offset) const
|
|
{
|
|
return dereference_adapter { m_cursor + offset };
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
// value_type operations
|
|
decltype(auto)
|
|
operator= (value_type const &rhs)
|
|
{
|
|
return **m_cursor = rhs;
|
|
}
|
|
|
|
decltype(auto) operator* () { return **m_cursor; }
|
|
decltype(auto) operator-> () { return **m_cursor; }
|
|
|
|
decltype(auto) operator* () const { return **m_cursor; }
|
|
decltype(auto) operator-> () const { return **m_cursor; }
|
|
|
|
|
|
private:
|
|
IteratorT m_cursor;
|
|
};
|
|
}
|