Merge 2019-07 LWG Motion 23

P1035R7 Input range adaptors

Fixes #3027.

Author: zygoloid

source/algorithms.tex

@@ -877,15 +877,15 @@
         count(I first, S last, const T& value, Proj proj = {});
     template<InputRange R, class T, class Proj = identity>
       requires IndirectRelation<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
-      constexpr iter_difference_t<iterator_t<R>>
+      constexpr range_difference_t<R>
         count(R&& r, const T& value, Proj proj = {});
     template<InputIterator I, Sentinel<I> S, class Proj = identity,
              IndirectUnaryPredicate<projected<I, Proj>> Pred>
       constexpr iter_difference_t<I>
         count_if(I first, S last, Pred pred, Proj proj = {});
     template<InputRange R, class Proj = identity,
              IndirectUnaryPredicate<projected<iterator_t<R>, Proj>> Pred>
-      constexpr iter_difference_t<iterator_t<R>>
+      constexpr range_difference_t<R>
         count_if(R&& r, Pred pred, Proj proj = {});
   }
 
@@ -1116,7 +1116,7 @@
              class Proj = identity>
       requires IndirectlyComparable<iterator_t<R>, const T*, Pred, Proj>
       constexpr safe_subrange_t<R>
-        search_n(R&& r, iter_difference_t<iterator_t<R>> count,
+        search_n(R&& r, range_difference_t<R> count,
                  const T& value, Pred pred = {}, Proj proj = {});
   }
 
@@ -1663,7 +1663,7 @@
              IndirectRelation<projected<iterator_t<R>, Proj>> C = ranges::equal_to>
       requires IndirectlyCopyable<iterator_t<R>, O> &&
                (ForwardIterator<iterator_t<R>> ||
-                (InputIterator<O> && Same<iter_value_t<iterator_t<R>>, iter_value_t<O>>) ||
+                (InputIterator<O> && Same<range_value_t<R>, iter_value_t<O>>) ||
                 IndirectlyCopyableStorable<iterator_t<R>, O>)
       constexpr unique_copy_result<safe_iterator_t<R>, O>
         unique_copy(R&& r, O result, C comp = {}, Proj proj = {});
@@ -2640,8 +2640,8 @@
       constexpr T min(initializer_list<T> r, Comp comp = {}, Proj proj = {});
     template<InputRange R, class Proj = identity,
              IndirectStrictWeakOrder<projected<iterator_t<R>, Proj>> Comp = ranges::less>
-      requires IndirectlyCopyableStorable<iterator_t<R>, iter_value_t<iterator_t<R>>*>
-      constexpr iter_value_t<iterator_t<R>>
+      requires IndirectlyCopyableStorable<iterator_t<R>, range_value_t<R>*>
+      constexpr range_value_t<R>
         min(R&& r, Comp comp = {}, Proj proj = {});
   }
 
@@ -2662,8 +2662,8 @@
       constexpr T max(initializer_list<T> r, Comp comp = {}, Proj proj = {});
     template<InputRange R, class Proj = identity,
              IndirectStrictWeakOrder<projected<iterator_t<R>, Proj>> Comp = ranges::less>
-      requires IndirectlyCopyableStorable<iterator_t<R>, iter_value_t<iterator_t<R>>*>
-      constexpr iter_value_t<iterator_t<R>>
+      requires IndirectlyCopyableStorable<iterator_t<R>, range_value_t<R>*>
+      constexpr range_value_t<R>
         max(R&& r, Comp comp = {}, Proj proj = {});
   }
 
@@ -2704,8 +2704,8 @@
         minmax(initializer_list<T> r, Comp comp = {}, Proj proj = {});
     template<InputRange R, class Proj = identity,
              IndirectStrictWeakOrder<projected<iterator_t<R>, Proj>> Comp = ranges::less>
-      requires IndirectlyCopyableStorable<iterator_t<R>, iter_value_t<iterator_t<R>>*>
-      constexpr minmax_result<iter_value_t<iterator_t<R>>>
+      requires IndirectlyCopyableStorable<iterator_t<R>, range_value_t<R>*>
+      constexpr minmax_result<range_value_t<R>>
         minmax(R&& r, Comp comp = {}, Proj proj = {});
   }
 
@@ -3512,15 +3512,15 @@
     ranges::count(I first, S last, const T& value, Proj proj = {});
 template<InputRange R, class T, class Proj = identity>
   requires IndirectRelation<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
-  constexpr iter_difference_t<iterator_t<R>>
+  constexpr range_difference_t<R>
     ranges::count(R&& r, const T& value, Proj proj = {});
 template<InputIterator I, Sentinel<I> S, class Proj = identity,
          IndirectUnaryPredicate<projected<I, Proj>> Pred>
   constexpr iter_difference_t<I>
     ranges::count_if(I first, S last, Pred pred, Proj proj = {});
 template<InputRange R, class Proj = identity,
          IndirectUnaryPredicate<projected<iterator_t<R>, Proj>> Pred>
-  constexpr iter_difference_t<iterator_t<R>>
+  constexpr range_difference_t<R>
     ranges::count_if(R&& r, Pred pred, Proj proj = {});
 \end{itemdecl}
 
@@ -4013,7 +4013,7 @@
          class Proj = identity>
   requires IndirectlyComparable<iterator_t<R>, const T*, Pred, Proj>
   constexpr safe_subrange_t<R>
-    ranges::search_n(R&& r, iter_difference_t<iterator_t<R>> count,
+    ranges::search_n(R&& r, range_difference_t<R> count,
                      const T& value, Pred pred = {}, Proj proj = {});
 \end{itemdecl}
 
@@ -5234,7 +5234,7 @@
          IndirectRelation<projected<iterator_t<R>, Proj>> C = ranges::equal_to>
   requires IndirectlyCopyable<iterator_t<R>, O> &&
            (ForwardIterator<iterator_t<R>> ||
-            (InputIterator<O> && Same<iter_value_t<iterator_t<R>>, iter_value_t<O>>) ||
+            (InputIterator<O> && Same<range_value_t<R>, iter_value_t<O>>) ||
             IndirectlyCopyableStorable<iterator_t<R>, O>)
   constexpr ranges::unique_copy_result<safe_iterator_t<R>, O>
     ranges::unique_copy(R&& r, O result, C comp = {}, Proj proj = {});
@@ -7913,8 +7913,8 @@
   constexpr T ranges::min(initializer_list<T> r, Comp comp = {}, Proj proj = {});
 template<InputRange R, class Proj = identity,
          IndirectStrictWeakOrder<projected<iterator_t<R>, Proj>> Comp = ranges::less>
-  requires IndirectlyCopyableStorable<iterator_t<R>, iter_value_t<iterator_t<R>>*>
-  constexpr iter_value_t<iterator_t<R>>
+  requires IndirectlyCopyableStorable<iterator_t<R>, range_value_t<R>*>
+  constexpr range_value_t<R>
     ranges::min(R&& r, Comp comp = {}, Proj proj = {});
 \end{itemdecl}
 
@@ -7990,8 +7990,8 @@
   constexpr T ranges::max(initializer_list<T> r, Comp comp = {}, Proj proj = {});
 template<InputRange R, class Proj = identity,
          IndirectStrictWeakOrder<projected<iterator_t<R>, Proj>> Comp = ranges::less>
-  requires IndirectlyCopyableStorable<iterator_t<R>, iter_value_t<iterator_t<R>>*>
-  constexpr iter_value_t<iterator_t<R>>
+  requires IndirectlyCopyableStorable<iterator_t<R>, range_value_t<R>*>
+  constexpr range_value_t<R>
     ranges::max(R&& r, Comp comp = {}, Proj proj = {});
 \end{itemdecl}
 
@@ -8070,8 +8070,8 @@
     ranges::minmax(initializer_list<T> r, Comp comp = {}, Proj proj = {});
 template<InputRange R, class Proj = identity,
          IndirectStrictWeakOrder<projected<iterator_t<R>, Proj>> Comp = ranges::less>
-  requires IndirectlyCopyableStorable<iterator_t<R>, iter_value_t<iterator_t<R>>*>
-  constexpr ranges::minmax_result<iter_value_t<iterator_t<R>>>
+  requires IndirectlyCopyableStorable<iterator_t<R>, range_value_t<R>*>
+  constexpr ranges::minmax_result<range_value_t<R>>
     ranges::minmax(R&& r, Comp comp = {}, Proj proj = {});
 \end{itemdecl}
 

source/iterators.tex

@@ -243,7 +243,7 @@
     template<Iterator I, Sentinel<I> S>
       constexpr iter_difference_t<I> distance(I first, S last);
     template<Range R>
-      constexpr iter_difference_t<iterator_t<R>> distance(R&& r);
+      constexpr range_difference_t<R> distance(R&& r);
 
     // \ref{range.iter.op.next}, \tcode{ranges::next}
     template<Iterator I>
@@ -2833,7 +2833,7 @@
 \indexlibrary{\idxcode{distance}}%
 \begin{itemdecl}
 template<Range R>
-  constexpr iter_difference_t<iterator_t<R>> ranges::distance(R&& r);
+  constexpr range_difference_t<R> ranges::distance(R&& r);
 \end{itemdecl}
 
 \begin{itemdescr}