P2302R4 std::ranges::contains

Author: jensmaurer

source/algorithms.tex

@@ -695,6 +695,29 @@
       constexpr bool none_of(R&& r, Pred pred, Proj proj = {});
   }
 
+  // \ref{alg.contains}, contains
+  namespace ranges {
+    template<@\libconcept{input_iterator}@ I, @\libconcept{sentinel_for}@<I> S, class T, class Proj = identity>
+      requires @\libconcept{indirect_binary_predicate}@<ranges::equal_to, projected<I, Proj>, const T*>
+      constexpr bool contains(I first, S last, const T& value, Proj proj = {});
+    template<@\libconcept{input_range}@ R, class T, class Proj = identity>
+      requires
+        @\libconcept{indirect_binary_predicate}@<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
+      constexpr bool contains(R&& r, const T& value, Proj proj = {});
+
+    template<@\libconcept{forward_iterator}@ I1, @\libconcept{sentinel_for}@<I1> S1,
+             @\libconcept{forward_iterator}@ I2, @\libconcept{sentinel_for}@<I2> S2,
+             class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
+      requires @\libconcept{indirectly_comparable}@<I1, I2, Pred, Proj1, Proj2>
+      constexpr bool contains_subrange(I1 first1, S1 last1, I2 first2, S2 last2,
+                                       Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
+    template<@\libconcept{forward_range}@ R1, @\libconcept{forward_range}@ R2,
+             class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
+      requires @\libconcept{indirectly_comparable}@<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
+      constexpr bool contains_subrange(R1&& r1, R2&& r2,
+                                       Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
+  }
+
   // \ref{alg.foreach}, for each
   template<class InputIterator, class Function>
     constexpr Function for_each(InputIterator first, InputIterator last, Function f);
@@ -3223,6 +3246,45 @@
 At most \tcode{last - first} applications of the predicate and any projection.
 \end{itemdescr}
 
+\rSec2[alg.contains]{Contains}
+
+\indexlibraryglobal{contains}%
+\begin{itemdecl}
+template<@\libconcept{input_iterator}@ I, @\libconcept{sentinel_for}@<I> S, class T, class Proj = identity>
+  requires @\libconcept{indirect_binary_predicate}@<ranges::equal_to, projected<I, Proj>, const T*>
+  constexpr bool ranges::contains(I first, S last, const T& value, Proj proj = {});
+template<@\libconcept{input_range}@ R, class T, class Proj = identity>
+  requires @\libconcept{indirect_binary_predicate}@<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
+  constexpr bool ranges::contains(R&& r, const T& value, Proj proj = {});
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\returns
+\tcode{ranges::find(std::move(first), last, value, proj) != last}.
+\end{itemdescr}
+
+\indexlibraryglobal{contains_subrange}%
+\begin{itemdecl}
+template<@\libconcept{forward_iterator}@ I1, @\libconcept{sentinel_for}@<I1> S1,
+         @\libconcept{forward_iterator}@ I2, @\libconcept{sentinel_for}@<I2> S2,
+         class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
+  requires @\libconcept{indirectly_comparable}@<I1, I2, Pred, Proj1, Proj2>
+  constexpr bool ranges::contains_subrange(I1 first1, S1 last1, I2 first2, S2 last2,
+                                           Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
+template<@\libconcept{forward_range}@ R1, @\libconcept{forward_range}@ R2,
+         class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
+  requires @\libconcept{indirectly_comparable}@<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
+  constexpr bool ranges::contains_subrange(R1&& r1, R2&& r2, Pred pred = {},
+                                           Proj1 proj1 = {}, Proj2 proj2 = {});
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\returns
+\tcode{first2 == last2 || !ranges::search(first1, last1, first2, last2, pred, proj1, proj2).empty()}.
+\end{itemdescr}
+
 \rSec2[alg.foreach]{For each}
 
 \indexlibraryglobal{for_each}%

source/support.tex

@@ -680,6 +680,7 @@
 #define @\defnlibxname{cpp_lib_ranges_as_const}@                   202207L // also in \libheader{ranges}
 #define @\defnlibxname{cpp_lib_ranges_chunk}@                      202202L // also in \libheader{ranges}
 #define @\defnlibxname{cpp_lib_ranges_chunk_by}@                   202202L // also in \libheader{ranges}
+#define @\defnlibxname{cpp_lib_ranges_contains}@                   202207L // also in \libheader{algorithm}
 #define @\defnlibxname{cpp_lib_ranges_iota}@                       202202L // also in \libheader{numeric}
 #define @\defnlibxname{cpp_lib_ranges_join_with}@                  202202L // also in \libheader{ranges}
 #define @\defnlibxname{cpp_lib_ranges_slide}@                      202202L // also in \libheader{ranges}