Add missing constraint to default constructors (#58)

lackhole · Oct 15, 2024 · 7224079 · 7224079
1 parent ce28b2e
commit 7224079
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Showing 24 changed files with 157 additions and 102 deletions.
diff --git a/.gitignore b/.gitignore
@@ -3,3 +3,4 @@
 
 .idea
 cmake-build-*
+build
diff --git a/include/preview/__ranges/movable_box.h b/include/preview/__ranges/movable_box.h
@@ -11,6 +11,7 @@
 
 #include "preview/__concepts/copyable.h"
 #include "preview/__concepts/copy_constructible.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__concepts/movable.h"
 #include "preview/__memory/addressof.h"
 #include "preview/optional.h"
@@ -44,7 +45,10 @@ struct movable_box_storage_base;
 template<typename T>
 struct movable_box_storage_base<T, true> {
 
-  constexpr movable_box_storage_base() = default;
+  template<bool B = default_initializable<T>::value, std::enable_if_t<B, int> = 0>
+  constexpr movable_box_storage_base()
+      noexcept(std::is_nothrow_default_constructible<T>::value)
+      : movable_box_storage_base(in_place) {}
   constexpr movable_box_storage_base(const movable_box_storage_base&) = default;
   constexpr movable_box_storage_base(movable_box_storage_base&&) = default;
   constexpr movable_box_storage_base& operator=(const movable_box_storage_base&) = default;
@@ -130,6 +134,11 @@ template<typename T>
 struct movable_box_storage_base<T, false> : private optional<T> {
   using base = optional<T>;
 
+  template<bool B = default_initializable<T>::value, std::enable_if_t<B, int> = 0>
+  constexpr movable_box_storage_base()
+  noexcept(std::is_nothrow_default_constructible<T>::value)
+      : base(in_place) {}
+
   using base::base;
   using base::operator=;
   using base::operator->;

diff --git a/include/preview/__ranges/owning_view.h b/include/preview/__ranges/owning_view.h
@@ -7,6 +7,7 @@
 
 #include <utility>
 
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__concepts/movable.h"
 #include "preview/__ranges/begin.h"
 #include "preview/__ranges/contiguous_range.h"
@@ -32,13 +33,14 @@ class owning_view : public view_interface<owning_view<R>> {
   static_assert(movable<R>::value, "Constraints not satisfied");
   static_assert(is_initializer_list<R>::value == false, "Constraints not satisfied");
 
-  constexpr owning_view() = default;
+  template<bool B = default_initializable<R>::value, std::enable_if_t<B, int> = 0>
+  constexpr owning_view() {}
+
   constexpr owning_view(owning_view&&) = default;
   constexpr owning_view(const owning_view&) = delete;
   constexpr owning_view(R&& t) noexcept(std::is_nothrow_move_constructible<R>::value)
       : r_(std::move(t)) {}
 
-
   owning_view& operator=(owning_view&&) = default;
   owning_view& operator=(const owning_view&) = delete;
 
@@ -68,7 +70,6 @@ class owning_view : public view_interface<owning_view<R>> {
     return ranges::end(r_);
   }
 
-
   template<typename T = R, std::enable_if_t<is_invocable<decltype(ranges::end), T&>::value, int> = 0>
   constexpr bool empty() {
     return ranges::empty(r_);
@@ -102,7 +103,7 @@ class owning_view : public view_interface<owning_view<R>> {
   }
 
  private:
-  R r_;
+  R r_ = R();
 };
 
 } // namespace ranges

diff --git a/include/preview/__ranges/subrange.h b/include/preview/__ranges/subrange.h
@@ -13,6 +13,7 @@
 #include "preview/__core/nodiscard.h"
 #include "preview/__concepts/convertible_to.h"
 #include "preview/__concepts/copyable.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__concepts/different_from.h"
 #include "preview/__concepts/same_as.h"
 #include "preview/__iterator/advance.h"
@@ -111,21 +112,25 @@ class subrange
   static_assert(sentinel_for<S, I>::value, "Constraints not satisfied");
   static_assert(K == subrange_kind::sized || !sized_sentinel_for<S, I>::value, "Constraints not satisfied");
 
-  subrange() = default;
+  template<bool B = default_initializable<I>::value, std::enable_if_t<B, int> = 0>
+  constexpr subrange() {}
 
   template<typename I2, std::enable_if_t<conjunction<
       detail::convertible_to_non_slicing<I2, I>,
       negation<StoreSize>
   >::value, int> = 0>
   constexpr subrange(I2 i, S s)
-      : iterator_(std::move(i)), sentinel_(std::move(s)) {}
+      : iterator_(std::move(i))
+      , sentinel_(std::move(s)) {}
 
   template<typename I2, std::enable_if_t<conjunction<
       detail::convertible_to_non_slicing<I2, I>,
       bool_constant< K == subrange_kind::sized >
   >::value, int> = 0>
   constexpr subrange(I2 i, S s, make_unsigned_like_t<iter_difference_t<I>> n)
-      : size_base(in_place, n), iterator_(std::move(i)), sentinel_(std::move(s)) {}
+      : size_base(in_place, n)
+      , iterator_(std::move(i))
+      , sentinel_(std::move(s)) {}
 
   template<typename R, std::enable_if_t<conjunction<
       different_from<subrange, R>,
@@ -158,7 +163,6 @@ class subrange
     return PairLike(iterator_, sentinel_);
   }
 
-
   template<typename I2 = I, std::enable_if_t<copyable<I2>::value, int> = 0>
   constexpr I begin() const {
     return iterator_;
@@ -240,8 +244,8 @@ class subrange
     ranges::advance(iterator_, n, sentinel_);
   }
 
-  I iterator_;
-  S sentinel_;
+  I iterator_{};
+  S sentinel_{};
 };
 
 // make-function for C++14

diff --git a/include/preview/__ranges/views/as_const_view.h b/include/preview/__ranges/views/as_const_view.h
@@ -8,6 +8,7 @@
 #include <utility>
 
 #include "preview/__concepts/copy_constructible.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__ranges/cbegin.h"
 #include "preview/__ranges/simple_view.h"
 #include "preview/__ranges/enable_borrowed_range.h"
@@ -25,7 +26,8 @@ class as_const_view : public view_interface<as_const_view<V>> {
   static_assert(view<V>::value, "Constraints not satisfied");
   static_assert(input_range<V>::value, "Constraints not satisfied");
 
-  as_const_view() = default;
+  template<bool B = default_initializable<V>::value, std::enable_if_t<B, int> = 0>
+  constexpr as_const_view() {}
 
   constexpr explicit as_const_view(V base)
       : base_(std::move(base)) {}

diff --git a/include/preview/__ranges/views/common_view.h b/include/preview/__ranges/views/common_view.h
@@ -9,6 +9,7 @@
 #include <utility>
 
 #include "preview/__concepts/copyable.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__iterator/common_iterator.h"
 #include "preview/__ranges/borrowed_range.h"
 #include "preview/__ranges/begin.h"
@@ -32,7 +33,8 @@ class common_view : public view_interface<common_view<V>> {
   static_assert(common_range<V>::value == false, "Constraints not satisfied");
   static_assert(copyable<iterator_t<V>>::value, "Constraints not satisfied");
 
-  common_view() = default;
+  template<bool B = default_initializable<V>::value, std::enable_if_t<B, int> = 0>
+  constexpr common_view() {}
 
   constexpr explicit common_view(V r)
       : base_(std::move(r)) {}

diff --git a/include/preview/__ranges/views/concat_view.h b/include/preview/__ranges/views/concat_view.h
@@ -11,6 +11,7 @@
 #include <utility>
 
 #include "preview/__core/inline_variable.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__iterator/next.h"
 #include "preview/__ranges/common_range.h"
 #include "preview/__ranges/simple_view.h"
@@ -375,8 +376,8 @@ struct concat_view : view_interface<concat_view<Rngs...>> {
 
   };
 
-
-  concat_view() = default;
+  template<bool B = default_initializable<std::tuple<Rngs...>>::value, std::enable_if_t<B, int> = 0>
+  constexpr concat_view() {}
 
   explicit concat_view(Rngs... rngs)
       : bases_{std::move(rngs)...} {}

diff --git a/include/preview/__ranges/views/drop_view.h b/include/preview/__ranges/views/drop_view.h
@@ -10,6 +10,7 @@
 #include <utility>
 
 #include "preview/__concepts/copy_constructible.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__iterator/next.h"
 #include "preview/__ranges/simple_view.h"
 #include "preview/__ranges/begin.h"
@@ -68,12 +69,12 @@ class drop_view : public detail::drop_view_cached_begin<drop_view<V>, V> {
  public:
   static_assert(view<V>::value, "Constraints not satisfied");
 
-  drop_view() = default;
+  template<bool B = default_initializable<V>::value, std::enable_if_t<B, int> = 0>
+  constexpr drop_view() {}
 
   constexpr explicit drop_view(V base, range_difference_t<V> count)
       : base_(std::move(base)), count_(count) {}
 
-
   template<typename Dummy = void, std::enable_if_t<conjunction<std::is_void<Dummy>,
       copy_constructible<V>
   >::value, int> = 0>

diff --git a/include/preview/__ranges/views/drop_while_view.h b/include/preview/__ranges/views/drop_while_view.h
@@ -10,6 +10,7 @@
 
 #include "preview/__algorithm/ranges/find_if_not.h"
 #include "preview/__concepts/copy_constructible.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__iterator/indirect_unary_predicate.h"
 #include "preview/__ranges/enable_borrowed_range.h"
 #include "preview/__ranges/end.h"
@@ -64,7 +65,8 @@ class drop_while_view
   static_assert(std::is_object<Pred>::value, "Constraints not satisfied");
   static_assert(indirect_unary_predicate<const Pred, iterator_t<V>>::value, "Constraints not satisfied");
 
-  drop_while_view() = default;
+  template<bool B = default_initializable<V>::value && default_initializable<Pred>::value, std::enable_if_t<B, int> = 0>
+  constexpr drop_while_view() {}
 
   constexpr explicit drop_while_view(V base, Pred pred)
       : base_(std::move(base)), pred_(std::move(pred)) {}

diff --git a/include/preview/__ranges/views/elements_view.h b/include/preview/__ranges/views/elements_view.h
@@ -12,6 +12,7 @@
 
 #include "preview/__concepts/copy_constructible.h"
 #include "preview/__concepts/convertible_to.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__concepts/derived_from.h"
 #include "preview/__concepts/move_constructible.h"
 #include "preview/__iterator/detail/have_cxx20_iterator.h"
@@ -128,7 +129,8 @@ class elements_view : public view_interface<elements_view<V, N>> {
     using reference = typename iterator_reference<range_reference_t<Base>>::type;
 #endif
 
-    iterator() = default;
+    template<bool B = default_initializable<iterator_t<Base>>::value, std::enable_if_t<B, int> = 0>
+    constexpr iterator() {}
 
     constexpr explicit iterator(iterator_t<Base> current)
         : current_(std::move(current)) {}
@@ -261,7 +263,7 @@ class elements_view : public view_interface<elements_view<V, N>> {
       return static_cast<E>(std::get<N>(*std::forward<T>(e)));
     }
 
-    iterator_t<Base> current_;
+    iterator_t<Base> current_{};
   };
 
   template<bool Const>
@@ -347,7 +349,8 @@ class elements_view : public view_interface<elements_view<V, N>> {
     sentinel_t<Base> end_;
   };
 
-  elements_view() = default;
+  template<bool B = default_initializable<V>::value, std::enable_if_t<B, int> = 0>
+  constexpr elements_view() {}
 
   constexpr explicit elements_view(V base)
       : base_(std::move(base)) {}
@@ -413,7 +416,7 @@ class elements_view : public view_interface<elements_view<V, N>> {
   }
 
  private:
-  V base_;
+  V base_{};
 };
 
 } // namespace ranges

diff --git a/include/preview/__ranges/views/enumerate_view.h b/include/preview/__ranges/views/enumerate_view.h
@@ -10,6 +10,7 @@
 
 #include "preview/__concepts/copy_constructible.h"
 #include "preview/__concepts/convertible_to.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__concepts/move_constructible.h"
 #include "preview/__iterator/iterator_tag.h"
 #include "preview/__iterator/iter_move.h"
@@ -89,7 +90,8 @@ class enumerate_view : public view_interface<enumerate_view<V>> {
     using pointer = void;
     using reference = Tuple<difference_type, range_reference_t<Base>>;
 
-    iterator() = default;
+    template<bool B = default_initializable<iterator_t<Base>>::value, std::enable_if_t<B, int> = 0>
+    constexpr iterator() {}
 
     template<bool AntiConst, std::enable_if_t<conjunction<
         bool_constant<((Const != AntiConst) && Const)>,
@@ -227,8 +229,8 @@ class enumerate_view : public view_interface<enumerate_view<V>> {
      }
 
    private:
-    iterator_t<Base> current_;
-    difference_type pos_;
+    iterator_t<Base> current_{};
+    difference_type pos_ = 0;
   };
 
   template<bool Const>
@@ -299,7 +301,8 @@ class enumerate_view : public view_interface<enumerate_view<V>> {
     sentinel_t<Base> end_;
   };
 
-  enumerate_view() = default;
+  template<bool B = default_initializable<V>::value, std::enable_if_t<B, int> = 0>
+  constexpr enumerate_view() {}
 
   constexpr explicit enumerate_view(V base)
       : base_(std::move(base)) {}

diff --git a/include/preview/__ranges/views/filter_view.h b/include/preview/__ranges/views/filter_view.h
@@ -12,6 +12,7 @@
 #include <utility>
 
 #include "preview/__algorithm/ranges/find_if.h"
+#include "preview/__concepts/default_initializable.h"
 #include "preview/__concepts/derived_from.h"
 #include "preview/__concepts/equality_comparable.h"
 #include "preview/__core/std_version.h"
@@ -142,7 +143,8 @@ class filter_view : public view_interface<filter_view<V, Pred>>, detail::filter_
     using reference = range_reference_t<V>;
 #endif
 
-    iterator() = default;
+    template<bool B = default_initializable<iterator_t<V>>::value, std::enable_if_t<B, int> = 0>
+    constexpr iterator() {}
 
     constexpr iterator(filter_view& parent, iterator_t<V> current)
         : current_(std::move(current))
@@ -265,10 +267,12 @@ class filter_view : public view_interface<filter_view<V, Pred>>, detail::filter_
 
   friend class iterator;
 
-  filter_view() = default;
+  template<bool B = default_initializable<V>::value && default_initializable<Pred>::value, std::enable_if_t<B, int> = 0>
+  constexpr filter_view() {}
 
   constexpr explicit filter_view(V base, Pred pred)
-      : base_(std::move(base)), pred_(std::move(pred)) {}
+      : base_(std::move(base))
+      , pred_(std::move(pred)) {}
 
   template<typename V2 = V, std::enable_if_t<copy_constructible<V2>::value, int> = 0>
   constexpr V base() const & {