Export of internal Abseil changes.

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6bab63b2bcdbd768743c2ebcc4a8e19af20c5406 by Abseil Team <absl-team@google.com>:

Reformats inlined_vector.h to match the current Google lint rules

PiperOrigin-RevId: 202154101

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00cdeda6ea24591a9cb8ac8b3c2e2a042e1b15b1 by Gennadiy Rozental <rogeeff@google.com>:

Improve SplitterIsConvertibleTo implementation.

PiperOrigin-RevId: 202095009

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7c24071afac45a17c47e819896f844a36e239bda by Greg Falcon <gfalcon@google.com>:

Internal change

PiperOrigin-RevId: 201991288
GitOrigin-RevId: 6bab63b2bcdbd768743c2ebcc4a8e19af20c5406
Change-Id: Ic5a988ab39e78247285411f36287cd34d6f5afd3

3 files changed, 53 insertions, 4 deletions

diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 3e50d24a322a..17831c208230 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -486,6 +486,9 @@ cc_test(
     srcs = [
         "charconv_benchmark.cc",
     ],
+    tags = [
+        "benchmark",
+    ],
     deps = [
         ":strings",
         "//absl/base",
diff --git a/absl/strings/internal/str_split_internal.h b/absl/strings/internal/str_split_internal.h
index a1b10f3addcf..9cf0833f4902 100644
--- a/absl/strings/internal/str_split_internal.h
+++ b/absl/strings/internal/str_split_internal.h
@@ -228,14 +228,31 @@ struct IsInitializerList
 // compiled in C++11 will get an error due to ambiguous conversion paths (in
 // C++11 std::vector<T>::operator= is overloaded to take either a std::vector<T>
 // or an std::initializer_list<T>).
+
+template <typename C, bool has_value_type, bool has_mapped_type>
+struct SplitterIsConvertibleToImpl : std::false_type {};
+
+template <typename C>
+struct SplitterIsConvertibleToImpl<C, true, false>
+    : std::is_constructible<typename C::value_type, absl::string_view> {};
+
+template <typename C>
+struct SplitterIsConvertibleToImpl<C, true, true>
+    : absl::conjunction<
+          std::is_constructible<typename C::key_type, absl::string_view>,
+          std::is_constructible<typename C::mapped_type, absl::string_view>> {};
+
 template <typename C>
 struct SplitterIsConvertibleTo
-    : std::enable_if<
+    : SplitterIsConvertibleToImpl<
+          C,
 #ifdef _GLIBCXX_DEBUG
           !IsStrictlyBaseOfAndConvertibleToSTLContainer<C>::value &&
 #endif  // _GLIBCXX_DEBUG
-          !IsInitializerList<C>::value && HasValueType<C>::value &&
-          HasConstIterator<C>::value> {
+              !IsInitializerList<
+                  typename std::remove_reference<C>::type>::value &&
+              HasValueType<C>::value && HasConstIterator<C>::value,
+          HasMappedType<C>::value> {
 };
 
 // This class implements the range that is returned by absl::StrSplit(). This
@@ -281,7 +298,8 @@ class Splitter {
   // An implicit conversion operator that is restricted to only those containers
   // that the splitter is convertible to.
   template <typename Container,
-            typename OnlyIf = typename SplitterIsConvertibleTo<Container>::type>
+            typename = typename std::enable_if<
+                SplitterIsConvertibleTo<Container>::value>::type>
   operator Container() const {  // NOLINT(runtime/explicit)
     return ConvertToContainer<Container, typename Container::value_type,
                               HasMappedType<Container>::value>()(*this);
diff --git a/absl/strings/str_split_test.cc b/absl/strings/str_split_test.cc
index c172a7629933..c6898863dc0e 100644
--- a/absl/strings/str_split_test.cc
+++ b/absl/strings/str_split_test.cc
@@ -37,6 +37,34 @@ using ::testing::ElementsAre;
 using ::testing::Pair;
 using ::testing::UnorderedElementsAre;
 
+TEST(Split, TraitsTest) {
+  static_assert(!absl::strings_internal::SplitterIsConvertibleTo<int>::value,
+                "");
+  static_assert(!absl::strings_internal::SplitterIsConvertibleTo<std::string>::value,
+                "");
+  static_assert(absl::strings_internal::SplitterIsConvertibleTo<
+                    std::vector<std::string>>::value,
+                "");
+  static_assert(
+      !absl::strings_internal::SplitterIsConvertibleTo<std::vector<int>>::value,
+      "");
+  static_assert(absl::strings_internal::SplitterIsConvertibleTo<
+                    std::vector<absl::string_view>>::value,
+                "");
+  static_assert(absl::strings_internal::SplitterIsConvertibleTo<
+                    std::map<std::string, std::string>>::value,
+                "");
+  static_assert(absl::strings_internal::SplitterIsConvertibleTo<
+                    std::map<absl::string_view, absl::string_view>>::value,
+                "");
+  static_assert(!absl::strings_internal::SplitterIsConvertibleTo<
+                    std::map<int, std::string>>::value,
+                "");
+  static_assert(!absl::strings_internal::SplitterIsConvertibleTo<
+                    std::map<std::string, int>>::value,
+                "");
+}
+
 // This tests the overall split API, which is made up of the absl::StrSplit()
 // function and the Delimiter objects in the absl:: namespace.
 // This TEST macro is outside of any namespace to require full specification of