From 703a75b6711dd6fa417c7af1a05933530f6c9fea Mon Sep 17 00:00:00 2001
From: namark <namark@disroot.org>
Date: Sat, 28 Aug 2021 16:30:47 +0400
Subject: [PATCH] indirect_range_referring_reference_t
basically ranges::ref_view
---
source/simple/support/misc.hpp | 55 +++++++++++++++++++++++++++-------
unit_tests/misc.cpp | 5 +++-
2 files changed, 49 insertions(+), 11 deletions(-)
diff --git a/source/simple/support/misc.hpp b/source/simple/support/misc.hpp
index 1ac05d9..8f9fa53 100644
--- a/source/simple/support/misc.hpp
+++ b/source/simple/support/misc.hpp
@@ -136,31 +136,66 @@ namespace simple::support
return {begin, static_cast<std::string_view::size_type>(end - begin)};
}
- // NOTE: maybe put in algorithm range wrappers instead?
+ // NOTE: maybe put in algorithm/range_wrappers.hpp instead?
+ // problem is, range_wrappers.hpp doesn't depend on anything,
+ // so need to also parameterize the range type, to keep it that way.
+ // A bit unrealisitic to expect ::limit() or arithmetic for generic range.
+ // but really don't want the includeee
template <typename Container,
typename = std::enable_if_t<is_range_v<Container>>>
- class index_range
+ class indirect_range_referring_reference_t
{
public:
+ using container_type = Container;
+ using size_type = typename container_type::size_type;
+ using iterator = typename container_type::iterator;
+ using const_iterator = typename container_type::const_iterator;
+
+ explicit indirect_range_referring_reference_t
+ (Container& container) : container(&container)
+ {}
+
+ auto begin() const
+ {
+ using std::begin;
+ return begin(*container);
+ }
+
+ auto end() const
+ {
+ using std::end;
+ return end(*container);
+ }
+ private:
+ Container* container;
+ };
+
+ template <typename Container,
+ typename = std::enable_if_t<is_range_v<Container>>>
+ class index_range
+ {
+ public:
using container_type = Container;
using size_type = typename container_type::size_type;
+
explicit index_range
(
- Container & container,
+ Container container,
range<size_type> index = range<size_type>::limit()
) :
- container(&container),
+ container(std::move(container)),
index(index)
{}
explicit index_range
(
- Container & container,
+ Container container,
range<typename Container::const_iterator> iterator_range
) :
- container(&container),
- index(iterator_range - container.begin())
+ container(std::move(container)),
+ // TODO: ADL the begin
+ index(iterator_range - this->container.begin())
{}
auto begin() const
@@ -169,7 +204,7 @@ namespace simple::support
{ return iter_at(index.upper()); }
private:
- Container* container;
+ Container container;
range<size_type> index;
auto iter_at(size_type index) const
@@ -178,8 +213,8 @@ namespace simple::support
using std::end;
using std::clamp;
- auto begin_ = begin(*container);
- auto end_ = end(*container);
+ auto begin_ = begin(container);
+ auto end_ = end(container);
// TODO: use container.size() if available
return begin_ + clamp(index, size_type{},
diff --git a/unit_tests/misc.cpp b/unit_tests/misc.cpp
index e295460..f7d82e3 100644
--- a/unit_tests/misc.cpp
+++ b/unit_tests/misc.cpp
@@ -115,7 +115,10 @@ void RangeReference()
assert( std::equal(begin(temporef), end(temporef),
begin(prefix), end(prefix)) );
- index_range permaref(stuff, {begin(stuff), end(stuff)});
+ index_range permaref{
+ indirect_range_referring_reference_t(stuff),
+ {begin(stuff), end(stuff)}
+ };
assert( std::equal(begin(permaref), end(permaref),
begin(prefix), end(prefix)) );
--
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