Export of internal Abseil changes

--
d857e6e1f9b09a3eb5abd890677a98b23346f07a by Abseil Team <absl-team@google.com>:

Simplify internal TryAcquireWithSpinning.

No point declaring the `result` variable: we can just return the results
directly.

PiperOrigin-RevId: 307045800

--
421952252bc23be51f47f7d23f3422bad1ed382c by Derek Mauro <dmauro@google.com>:

Add custom sink support for `absl::Format()` through an ADL extension mechanism.

Users can now define
`void AbslFormatFlush(MySink* dest, absl::string_view part)`
to allow `absl::Format()` to append to a custom sink.

PiperOrigin-RevId: 306929052

--
c73d5cdb62cd58ea421ed1aeeab78a0ffcfeeefb by Matt Calabrese <calabrese@google.com>:

Internal-only conformance-testing macro ABSL_INTERNAL_ASSERT_CONFORMANCE_OF for compile-time and runtime checks of a specified type, expected properties of that type, and a logically-ordered series of equivalence classes of that type.

PiperOrigin-RevId: 306885512

--
a8c2495a07f37d68907855e3f0535bd5c27a3b52 by Abseil Team <absl-team@google.com>:

Internal change

PiperOrigin-RevId: 306766753
GitOrigin-RevId: d857e6e1f9b09a3eb5abd890677a98b23346f07a
Change-Id: Ic23c92ac74f9ffcbb2471ff8c6691f4b7b20354b

1 files changed, 246 insertions, 0 deletions

diff --git a/absl/types/internal/transform_args.h b/absl/types/internal/transform_args.h
new file mode 100644
index 0000000..4a0ab42
--- /dev/null
+++ b/absl/types/internal/transform_args.h
@@ -0,0 +1,246 @@
+// Copyright 2019 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
+//
+//      https://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.
+//
+// -----------------------------------------------------------------------------
+// transform_args.h
+// -----------------------------------------------------------------------------
+//
+// This file contains a higher-order macro that "transforms" each element of a
+// a variadic argument by a provided secondary macro.
+
+#ifndef ABSL_TYPES_INTERNAL_TRANSFORM_ARGS_H_
+#define ABSL_TYPES_INTERNAL_TRANSFORM_ARGS_H_
+
+//
+// ABSL_INTERNAL_CAT(a, b)
+//
+// This macro takes two arguments and concatenates them together via ## after
+// expansion.
+//
+// Example:
+//
+//   ABSL_INTERNAL_CAT(foo_, bar)
+//
+// Results in:
+//
+//   foo_bar
+#define ABSL_INTERNAL_CAT(a, b) ABSL_INTERNAL_CAT_IMPL(a, b)
+#define ABSL_INTERNAL_CAT_IMPL(a, b) a##b
+
+//
+// ABSL_INTERNAL_TRANSFORM_ARGS(m, ...)
+//
+// This macro takes another macro as an argument followed by a trailing series
+// of additional parameters (up to 32 additional arguments). It invokes the
+// passed-in macro once for each of the additional arguments, with the
+// expansions separated by commas.
+//
+// Example:
+//
+//   ABSL_INTERNAL_TRANSFORM_ARGS(MY_MACRO, a, b, c)
+//
+// Results in:
+//
+//   MY_MACRO(a), MY_MACRO(b), MY_MACRO(c)
+//
+// TODO(calabrese) Handle no arguments as a special case.
+#define ABSL_INTERNAL_TRANSFORM_ARGS(m, ...)             \
+  ABSL_INTERNAL_CAT(ABSL_INTERNAL_TRANSFORM_ARGS,        \
+                    ABSL_INTERNAL_NUM_ARGS(__VA_ARGS__)) \
+  (m, __VA_ARGS__)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS1(m, a0) m(a0)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS2(m, a0, a1) m(a0), m(a1)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS3(m, a0, a1, a2) m(a0), m(a1), m(a2)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS4(m, a0, a1, a2, a3) \
+  m(a0), m(a1), m(a2), m(a3)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS5(m, a0, a1, a2, a3, a4) \
+  m(a0), m(a1), m(a2), m(a3), m(a4)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS6(m, a0, a1, a2, a3, a4, a5) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS7(m, a0, a1, a2, a3, a4, a5, a6) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS8(m, a0, a1, a2, a3, a4, a5, a6, a7) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS9(m, a0, a1, a2, a3, a4, a5, a6, a7, a8) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS10(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9)                                    \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS11(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10)                               \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9), m(a10)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS12(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11)                          \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS13(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12)                     \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS14(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13)                \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS15(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14)           \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS16(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15)      \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS17(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS18(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17)                                   \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS19(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17, a18)                              \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS20(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17, a18, a19)                         \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS21(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17, a18, a19, a20)                    \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS22(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17, a18, a19, a20, a21)               \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS23(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17, a18, a19, a20, a21, a22)          \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS24(m, a0, a1, a2, a3, a4, a5, a6, a7, a8, \
+                                       a9, a10, a11, a12, a13, a14, a15, a16, \
+                                       a17, a18, a19, a20, a21, a22, a23)     \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22), m(a23)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS25(m, a0, a1, a2, a3, a4, a5, a6, a7, a8,  \
+                                       a9, a10, a11, a12, a13, a14, a15, a16,  \
+                                       a17, a18, a19, a20, a21, a22, a23, a24) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),        \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18),  \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS26(                                       \
+    m, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,  \
+    a16, a17, a18, a19, a20, a21, a22, a23, a24, a25)                         \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS27(                                       \
+    m, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,  \
+    a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26)                    \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25), m(a26)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS28(                                       \
+    m, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,  \
+    a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27)               \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25), m(a26), m(a27)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS29(                                       \
+    m, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,  \
+    a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28)          \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25), m(a26), m(a27), \
+      m(a28)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS30(                                       \
+    m, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,  \
+    a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29)     \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),       \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18), \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25), m(a26), m(a27), \
+      m(a28), m(a29)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS31(                                        \
+    m, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,   \
+    a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30) \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),        \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18),  \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25), m(a26), m(a27),  \
+      m(a28), m(a29), m(a30)
+
+#define ABSL_INTERNAL_TRANSFORM_ARGS32(m, a0, a1, a2, a3, a4, a5, a6, a7, a8,  \
+                                       a9, a10, a11, a12, a13, a14, a15, a16,  \
+                                       a17, a18, a19, a20, a21, a22, a23, a24, \
+                                       a25, a26, a27, a28, a29, a30, a31)      \
+  m(a0), m(a1), m(a2), m(a3), m(a4), m(a5), m(a6), m(a7), m(a8), m(a9),        \
+      m(a10), m(a11), m(a12), m(a13), m(a14), m(a15), m(a16), m(a17), m(a18),  \
+      m(a19), m(a20), m(a21), m(a22), m(a23), m(a24), m(a25), m(a26), m(a27),  \
+      m(a28), m(a29), m(a30), m(a31)
+
+#define ABSL_INTERNAL_NUM_ARGS_IMPL(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9,    \
+                                    a10, a11, a12, a13, a14, a15, a16, a17,    \
+                                    a18, a19, a20, a21, a22, a23, a24, a25,    \
+                                    a26, a27, a28, a29, a30, a31, result, ...) \
+  result
+
+#define ABSL_INTERNAL_FORCE_EXPANSION(...) __VA_ARGS__
+
+#define ABSL_INTERNAL_NUM_ARGS(...)                                            \
+  ABSL_INTERNAL_FORCE_EXPANSION(ABSL_INTERNAL_NUM_ARGS_IMPL(                   \
+      __VA_ARGS__, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, \
+      17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, ))
+
+#endif  // ABSL_TYPES_INTERNAL_TRANSFORM_ARGS_H_