Skip to content

Address iterator_category failing to compile for input iterators #27

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ednolan merged 1 commit into from
Nov 14, 2024
Merged

Address iterator_category failing to compile for input iterators #27

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 6 additions & 6 deletions include/beman/iterator_interface/iterator_interface.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -142,6 +142,7 @@ struct iter_cat<IteratorConcept, ReferenceType, false> {};

template <typename IteratorConcept, typename ReferenceType>
struct iter_cat<IteratorConcept, ReferenceType, true> {
private:
static constexpr auto compute_category_tag() {
if constexpr (!std::is_reference_v<ReferenceType>) {
return std::input_iterator_tag{};
Expand All @@ -154,19 +155,18 @@ struct iter_cat<IteratorConcept, ReferenceType, true> {
}
}

using TagType = std::invoke_result_t<decltype(compute_category_tag)>;
using iterator_category = TagType;
public:
using iterator_category = std::invoke_result_t<decltype(compute_category_tag)>;
};

} // namespace detail

template <class IteratorConcept, class ValueType, class Reference, class Pointer, class DifferenceType>
class iterator_interface {
class iterator_interface
: detail::iter_cat<IteratorConcept, Reference, std::derived_from<IteratorConcept, std::forward_iterator_tag>>
{
public:
using iterator_concept = IteratorConcept;
using iterator_category =
detail::iter_cat<IteratorConcept, Reference, std::derived_from<IteratorConcept, std::forward_iterator_tag>>::
iterator_category;
using value_type = remove_const_t<ValueType>;
using reference = Reference;
using pointer = conditional_t<is_same_v<iterator_concept, output_iterator_tag>, void, Pointer>;
Expand Down
30 changes: 30 additions & 0 deletions tests/beman/iterator_interface/iterator_interface.test.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
#include <gtest/gtest.h>

#include <algorithm>
#include <iterator>
#include <ranges>

namespace beman {
Expand Down Expand Up @@ -119,5 +120,34 @@ TEST(IteratorTest, OperatorArrow) {
ASSERT_EQ(ai->f(), 3);
}

struct dummy_input_iterator :
public ext_iterator_interface_compat<
dummy_input_iterator, std::input_iterator_tag, int, int const&, void, std::ptrdiff_t> {
constexpr dummy_input_iterator() { }
dummy_input_iterator(dummy_input_iterator const&) = delete;
dummy_input_iterator& operator=(dummy_input_iterator const&) = delete;
dummy_input_iterator(dummy_input_iterator&&) = default;
dummy_input_iterator& operator=(dummy_input_iterator&&) = default;
constexpr reference operator*() const {
return foo;
}
constexpr dummy_input_iterator& operator++() {
return *this;
}
constexpr void operator++(int) {}

friend constexpr bool operator==(std::default_sentinel_t const&,
dummy_input_iterator const&) {
return true;
}

friend beman::iterator_interface::iterator_interface_access;

int foo = 0;
};

static_assert(std::input_iterator<dummy_input_iterator>);
static_assert(!std::forward_iterator<dummy_input_iterator>);

} // namespace iterator_interface
} // namespace beman
Loading