Changes imported from Abseil "staging" branch:

- 0320844dcd8219965647f86db7c6c7296e40e41e Introduce internal macros for inline variable emulation s... by Matt Calabrese <calabrese@google.com>
  - 85197d0105805e6aab3a0a648351cb1582a61be0 Internal change. by Alex Strelnikov <strel@google.com>

GitOrigin-RevId: 0320844dcd8219965647f86db7c6c7296e40e41e
Change-Id: I7dce37f6839ff099462951059a9047c5c9377638

absl/utility/BUILD.bazel

@@ -10,7 +10,6 @@ licenses(["notice"])  # Apache 2.0
 
 cc_library(
     name = "utility",
-    srcs = ["utility.cc"],
     hdrs = ["utility.h"],
     copts = ABSL_DEFAULT_COPTS,
     deps = [

absl/utility/CMakeLists.txt

@@ -22,7 +22,6 @@ list(APPEND UTILITY_PUBLIC_HEADERS
 
 
 list(APPEND UTILITY_SRC
-  "utility.cc"
   ${UTILITY_PUBLIC_HEADERS}
 )
 

absl/utility/utility.cc

@@ -1,27 +0,0 @@
-// Copyright 2017 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// -----------------------------------------------------------------------------
-// File: ascii.h
-// -----------------------------------------------------------------------------
-//
-#include "absl/utility/utility.h"
-
-namespace absl {
-
-#ifndef ABSL_HAVE_STD_OPTIONAL
-const in_place_t in_place{};
-#endif
-
-}  // namespace absl

absl/utility/utility.h

@@ -45,6 +45,7 @@
 #include <utility>
 
 #include "absl/base/config.h"
+#include "absl/base/internal/inline_variable.h"
 #include "absl/base/internal/invoke.h"
 #include "absl/meta/type_traits.h"
 
@@ -155,7 +156,8 @@ using std::in_place;
 // `absl::optional`, designed to be a drop-in replacement for C++17's
 // `std::in_place_t`.
 struct in_place_t {};
-extern const in_place_t in_place;
+
+ABSL_INTERNAL_INLINE_CONSTEXPR(in_place_t, in_place, {});
 
 #endif  // ABSL_HAVE_STD_OPTIONAL