Implement the plugin-based version of std::search. There are no searchers yet; those are coming soon.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@242679 91177308-0d34-0410-b5e6-96231b3b80d8

include/experimental/algorithm

@@ -50,6 +50,12 @@ SampleIterator sample(PopulationIterator first, PopulationIterator last,
 _LIBCPP_BEGIN_NAMESPACE_LFTS
 
 
+template <class _ForwardIterator, class _Searcher>
+_LIBCPP_INLINE_VISIBILITY
+_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
+{ return __s(__f, __l); }
+
+
 template <class _PopulationIterator, class _SampleIterator, class _Distance,
           class _UniformRandomNumberGenerator>
 _LIBCPP_INLINE_VISIBILITY

test/std/experimental/algorithms/alg.search/search.pass.cpp

@@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+
+//   template<class ForwardIterator, class Searcher>
+//   ForwardIterator search(ForwardIterator first, ForwardIterator last,
+//                          const Searcher& searcher);
+//
+//		returns searcher.operator(first, last)
+//
+
+#include <experimental/algorithm>
+#include <cassert>
+
+#include "test_iterators.h"
+
+int searcher_called = 0;
+
+struct MySearcher {
+    template <typename Iterator>
+    Iterator operator() ( Iterator b, Iterator /*e*/) const 
+    {
+        ++searcher_called;
+        return b;
+    }
+};
+
+
+int main() {
+    typedef int * RI;
+    static_assert(std::is_same<RI, decltype(std::experimental::search(RI(), RI(), MySearcher()))>::value, "" );
+
+    RI it{nullptr};
+    assert(it == std::experimental::search(it, it, MySearcher()));
+    assert(searcher_called == 1);
+}