Changes imported from Abseil "staging" branch:

  - 20f4e7133d695e9a05e13ebdfd4d78da310b42b5 Remove the warning supressions -Wno-documentation and by Derek Mauro <dmauro@google.com>
  - e1bde85c0571673b1e7a88b9d45a393606ba7e6c Changed the optimized version of strings_internal::JoinAl... by Abseil Team <absl-team@google.com>
  - 746e6716b4c15be61547670d68d25a1c850d3954 Add missing absl:: qualification. by Alex Strelnikov <strel@google.com>
  - 4e5c18c488cbd49ca72b02911cf22d830d5a7f16 Internals change: Remove the ability to pass a custom met... by Greg Falcon <gfalcon@google.com>
  - 65d58107a5730d4b6468bbffc72bea2f980af826 Moved most common character case (ascii printable) out of... by Abseil Team <absl-team@google.com>
  - f031331cc55a3d57b9110e12c7cbe50ac3e2a04f Add missing copyright headers to a few source files. by Greg Falcon <gfalcon@google.com>
  - 6035a77af6fa951c536b42df4c710d16d1817aec Enable libstdc++'s memcmp optimization in absl::equal for... by Abseil Team <absl-team@google.com>
  - 73a665a4a10781e5d89f75a876ece7ad859f4116 Fix minor spelling error "hexidecimal". by Abseil Team <absl-team@google.com>

GitOrigin-RevId: 20f4e7133d695e9a05e13ebdfd4d78da310b42b5
Change-Id: Id8c18ebd331d096935052a6ab259ebe0e2ef13ae

1 files changed, 12 insertions, 0 deletions

diff --git a/absl/algorithm/algorithm.h b/absl/algorithm/algorithm.h
index 341b68b0..3d658643 100644
--- a/absl/algorithm/algorithm.h
+++ b/absl/algorithm/algorithm.h
@@ -59,6 +59,18 @@ bool EqualImpl(InputIter1 first1, InputIter1 last1, InputIter2 first2,
          std::equal(first1, last1, first2, std::forward<Pred>(pred));
 }
 
+// When we are using our own internal predicate that just applies operator==, we
+// forward to the non-predicate form of std::equal. This enables an optimization
+// in libstdc++ that can result in std::memcmp being used for integer types.
+template <typename InputIter1, typename InputIter2>
+bool EqualImpl(InputIter1 first1, InputIter1 last1, InputIter2 first2,
+               InputIter2 last2, algorithm_internal::EqualTo /* unused */,
+               std::random_access_iterator_tag,
+               std::random_access_iterator_tag) {
+  return (last1 - first1 == last2 - first2) &&
+         std::equal(first1, last1, first2);
+}
+
 template <typename It>
 It RotateImpl(It first, It middle, It last, std::true_type) {
   return std::rotate(first, middle, last);