From a35dc5f34bac6139cd8394311ef9d7dbffdd02b0 Mon Sep 17 00:00:00 2001
From: namark <namark@disroot.org>
Date: Wed, 26 Aug 2020 03:34:07 +0400
Subject: [PATCH] Iterator type alias in iterator ranges.
---
source/simple/support/range.hpp | 23 +++++++++++++----------
unit_tests/range.cpp | 7 +++++++
2 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/source/simple/support/range.hpp b/source/simple/support/range.hpp
index 6bc1501..074bf0d 100644
--- a/source/simple/support/range.hpp
+++ b/source/simple/support/range.hpp
@@ -13,10 +13,10 @@ namespace simple::support
{
template<typename Type, typename = std::nullptr_t>
- struct range_based_for_loopable : public std::false_type {};
+ struct is_iterable : public std::false_type {};
template<typename Type>
- struct range_based_for_loopable<Type,
+ struct is_iterable<Type,
decltype(
void(std::declval<Type>() != std::declval<Type>()),
void(*std::declval<Type>()),
@@ -31,6 +31,9 @@ namespace simple::support
array<Type, 2> bounds;
+ using iterator = std::conditional_t<is_iterable<Type>{},
+ Type, void>;
+
constexpr static range limit()
{
static_assert(std::numeric_limits<Type>::is_specialized);
@@ -47,19 +50,19 @@ namespace simple::support
return bounds == other.bounds;
}
- template <typename T = Type,
- std::enable_if_t<range_based_for_loopable<T>{}>...>
+ template <typename It = Type,
+ std::enable_if_t<is_iterable<It>{}>...>
[[nodiscard]] constexpr Type begin() const { return lower(); }
- template <typename T = Type,
- std::enable_if_t<range_based_for_loopable<T>{}>...>
+ template <typename It = Type,
+ std::enable_if_t<is_iterable<It>{}>...>
[[nodiscard]] constexpr Type end() const { return upper(); }
- template <typename T = Type,
- std::enable_if_t<range_based_for_loopable<T>{}>...>
+ template <typename It = Type,
+ std::enable_if_t<is_iterable<It>{}>...>
[[nodiscard]] constexpr auto rbegin() const
{ return std::make_reverse_iterator(upper()); }
- template <typename T = Type,
- std::enable_if_t<range_based_for_loopable<T>{}>...>
+ template <typename It = Type,
+ std::enable_if_t<is_iterable<It>{}>...>
[[nodiscard]] constexpr auto rend() const
{ return std::make_reverse_iterator(lower()); }
diff --git a/unit_tests/range.cpp b/unit_tests/range.cpp
index 3851611..e7852aa 100644
--- a/unit_tests/range.cpp
+++ b/unit_tests/range.cpp
@@ -235,6 +235,12 @@ void Arithmetic()
}
}
+void Iterator()
+{
+ static_assert(std::is_same_v<int*, range<int*>::iterator>);
+ static_assert(std::is_same_v<void, range<int>::iterator>);
+}
+
constexpr bool Constexprness()
{
range<int> v{};
@@ -289,6 +295,7 @@ int main()
SubRange();
Limit();
Arithmetic();
+ Iterator();
static_assert(Constexprness());
return 0;
}
--
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