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-rw-r--r--absl/base/BUILD.bazel7
-rw-r--r--absl/base/attributes.h226
-rw-r--r--absl/base/call_once.h4
-rw-r--r--absl/base/call_once_test.cc4
-rw-r--r--absl/base/config_test.cc1
-rw-r--r--absl/base/dynamic_annotations.h2
-rw-r--r--absl/base/internal/atomic_hook.h2
-rw-r--r--absl/base/internal/endian_test.cc2
-rw-r--r--absl/base/internal/low_level_alloc.cc10
-rw-r--r--absl/base/internal/low_level_alloc.h2
-rw-r--r--absl/base/internal/low_level_alloc_test.cc2
-rw-r--r--absl/base/internal/low_level_scheduling.h2
-rw-r--r--absl/base/internal/malloc_extension.cc3
-rw-r--r--absl/base/internal/malloc_extension.h7
-rw-r--r--absl/base/internal/malloc_hook.cc7
-rw-r--r--absl/base/internal/raw_logging.cc9
-rw-r--r--absl/base/internal/raw_logging.h1
-rw-r--r--absl/base/internal/spinlock.cc2
-rw-r--r--absl/base/internal/spinlock.h6
-rw-r--r--absl/base/internal/spinlock_wait.h1
-rw-r--r--absl/base/internal/sysinfo.cc1
-rw-r--r--absl/base/internal/thread_identity_test.cc1
-rw-r--r--absl/base/internal/unscaledcycleclock.h1
-rw-r--r--absl/base/invoke_test.cc1
-rw-r--r--absl/base/spinlock_test_common.cc2
-rw-r--r--absl/base/throw_delegate_test.cc1
-rw-r--r--absl/numeric/int128.h5
-rw-r--r--absl/synchronization/BUILD.bazel12
-rw-r--r--absl/synchronization/barrier_test.cc75
-rw-r--r--absl/time/duration_test.cc1
-rw-r--r--absl/time/format_test.cc1
-rw-r--r--absl/types/optional.h38
-rw-r--r--absl/types/optional_test.cc50
-rw-r--r--absl/utility/utility.h106
34 files changed, 442 insertions, 153 deletions
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index 87a6d3e6..2e023ef2 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -121,6 +121,7 @@ cc_library(
":config",
":core_headers",
":dynamic_annotations",
+ ":spinlock_wait",
],
)
@@ -192,6 +193,7 @@ cc_library(
deps = [
":base",
":config",
+ ":core_headers",
],
)
@@ -236,6 +238,8 @@ cc_library(
copts = ABSL_TEST_COPTS,
deps = [
":base",
+ ":core_headers",
+ ":spinlock_wait",
"//absl/synchronization",
"@com_google_googletest//:gtest",
],
@@ -249,6 +253,8 @@ cc_test(
copts = ABSL_TEST_COPTS,
deps = [
":base",
+ ":core_headers",
+ ":spinlock_wait",
"//absl/synchronization",
"@com_google_googletest//:gtest_main",
],
@@ -342,6 +348,7 @@ cc_test(
}),
deps = [
":base",
+ ":core_headers",
"//absl/synchronization",
] + select(GUNIT_MAIN_DEPS_SELECTOR),
)
diff --git a/absl/base/attributes.h b/absl/base/attributes.h
index 5eecdabe..c2155a4e 100644
--- a/absl/base/attributes.h
+++ b/absl/base/attributes.h
@@ -12,39 +12,61 @@
// See the License for the specific language governing permissions and
// limitations under the License.
//
-// Various macros for C++ attributes
+// This header file defines macros for declaring attributes for functions,
+// types, and variables.
+//
+// These macros are used within Abseil and allow the compiler to optimize, where
+// applicable, certain function calls.
+//
// This file is used for both C and C++!
//
// Most macros here are exposing GCC or Clang features, and are stubbed out for
// other compilers.
+//
// GCC attributes documentation:
-// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html
-// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Variable-Attributes.html
-// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Type-Attributes.html
-//
-// Most attributes in this file are already supported by GCC 4.7.
-// However, some of them are not supported in older version of Clang.
-// Thus, we check __has_attribute() first. If the check fails, we check if we
-// are on GCC and assume the attribute exists on GCC (which is verified on GCC
-// 4.7).
-//
-// For sanitizer-related attributes, define the following macros
-// using -D along with the given value for -fsanitize:
-// - ADDRESS_SANITIZER with -fsanitize=address (GCC 4.8+, Clang)
-// - MEMORY_SANITIZER with -fsanitize=memory (Clang)
-// - THREAD_SANITIZER with -fsanitize=thread (GCC 4.8+, Clang)
-// - UNDEFINED_BEHAVIOR_SANITIZER with -fsanitize=undefined (GCC 4.9+, Clang)
-// - CONTROL_FLOW_INTEGRITY with -fsanitize=cfi (Clang)
-// Since these are only supported by GCC and Clang now, we only check for
-// __GNUC__ (GCC or Clang) and the above macros.
+// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html
+// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Variable-Attributes.html
+// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Type-Attributes.html
+//
+// Most attributes in this file are already supported by GCC 4.7. However, some
+// of them are not supported in older version of Clang. Thus, we check
+// `__has_attribute()` first. If the check fails, we check if we are on GCC and
+// assume the attribute exists on GCC (which is verified on GCC 4.7).
+//
+// -----------------------------------------------------------------------------
+// Sanitizer Attributes
+// -----------------------------------------------------------------------------
+//
+// Sanitizer-related attributes are not "defined" in this file (and indeed
+// are not defined as such in any file). To utilize the following
+// sanitizer-related attributes within your builds, define the following macros
+// within your build using a `-D` flag, along with the given value for
+// `-fsanitize`:
+//
+// * `ADDRESS_SANITIZER` + `-fsanitize=address` (Clang, GCC 4.8)
+// * `MEMORY_SANITIZER` + `-fsanitize=memory` (Clang-only)
+// * `THREAD_SANITIZER + `-fsanitize=thread` (Clang, GCC 4.8+)
+// * `UNDEFINED_BEHAVIOR_SANITIZER` + `-fsanitize=undefined` (Clang, GCC 4.9+)
+// * `CONTROL_FLOW_INTEGRITY` + -fsanitize=cfi (Clang-only)
+//
+// Example:
+//
+// // Enable branches in the Abseil code that are tagged for ASan:
+// $ bazel -D ADDRESS_SANITIZER -fsanitize=address *target*
+//
+// Since these macro names are only supported by GCC and Clang, we only check
+// for `__GNUC__` (GCC or Clang) and the above macros.
#ifndef ABSL_BASE_ATTRIBUTES_H_
#define ABSL_BASE_ATTRIBUTES_H_
-// ABSL_HAVE_ATTRIBUTE is a function-like feature checking macro.
-// It's a wrapper around __has_attribute, which is defined by GCC 5+ and Clang.
-// It evaluates to a nonzero constant integer if the attribute is supported
-// or 0 if not.
-// It evaluates to zero if __has_attribute is not defined by the compiler.
+// ABSL_HAVE_ATTRIBUTE
+//
+// A function-like feature checking macro that is a wrapper around
+// `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a
+// nonzero constant integer if the attribute is supported or 0 if not.
+//
+// It evaluates to zero if `__has_attribute` is not defined by the compiler.
+//
// GCC: https://gcc.gnu.org/gcc-5/changes.html
// Clang: https://clang.llvm.org/docs/LanguageExtensions.html
#ifdef __has_attribute
@@ -53,11 +75,12 @@
#define ABSL_HAVE_ATTRIBUTE(x) 0
#endif
-// ABSL_HAVE_CPP_ATTRIBUTE is a function-like feature checking macro that
-// accepts C++11 style attributes. It's a wrapper around __has_cpp_attribute,
-// defined by ISO C++ SD-6
+// ABSL_HAVE_CPP_ATTRIBUTE
+//
+// A function-like feature checking macro that accepts C++11 style attributes.
+// It's a wrapper around `__has_cpp_attribute`, defined by ISO C++ SD-6
// (http://en.cppreference.com/w/cpp/experimental/feature_test). If we don't
-// find __has_cpp_attribute, will evaluate to 0.
+// find `__has_cpp_attribute`, will evaluate to 0.
#if defined(__cplusplus) && defined(__has_cpp_attribute)
// NOTE: requiring __cplusplus above should not be necessary, but
// works around https://bugs.llvm.org/show_bug.cgi?id=23435.
@@ -69,15 +92,18 @@
// -----------------------------------------------------------------------------
// Function Attributes
// -----------------------------------------------------------------------------
+//
// GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
// Clang: https://clang.llvm.org/docs/AttributeReference.html
-// ABSL_PRINTF_ATTRIBUTE, ABSL_SCANF_ATTRIBUTE
-// Tell the compiler to do printf format std::string checking if the
+// ABSL_PRINTF_ATTRIBUTE
+// ABSL_SCANF_ATTRIBUTE
+//
+// Tells the compiler to perform `printf` format std::string checking if the
// compiler supports it; see the 'format' attribute in
// <http://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html>.
//
-// N.B.: As the GCC manual states, "[s]ince non-static C++ methods
+// Note: As the GCC manual states, "[s]ince non-static C++ methods
// have an implicit 'this' argument, the arguments of such methods
// should be counted from two, not one."
#if ABSL_HAVE_ATTRIBUTE(format) || (defined(__GNUC__) && !defined(__clang__))
@@ -90,9 +116,10 @@
#define ABSL_SCANF_ATTRIBUTE(string_index, first_to_check)
#endif
-// ABSL_ATTRIBUTE_ALWAYS_INLINE, ABSL_ATTRIBUTE_NOINLINE
-// For functions we want to force inline or not inline.
-// Introduced in gcc 3.1.
+// ABSL_ATTRIBUTE_ALWAYS_INLINE
+// ABSL_ATTRIBUTE_NOINLINE
+//
+// Forces functions to either inline or not inline. Introduced in gcc 3.1.
#if ABSL_HAVE_ATTRIBUTE(always_inline) || \
(defined(__GNUC__) && !defined(__clang__))
#define ABSL_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline))
@@ -109,7 +136,8 @@
#endif
// ABSL_ATTRIBUTE_NO_TAIL_CALL
-// Prevent the compiler from optimizing away stack frames for functions which
+//
+// Prevents the compiler from optimizing away stack frames for functions which
// end in a call to another function.
#if ABSL_HAVE_ATTRIBUTE(disable_tail_calls)
#define ABSL_HAVE_ATTRIBUTE_NO_TAIL_CALL 1
@@ -122,8 +150,10 @@
#define ABSL_ATTRIBUTE_NO_TAIL_CALL
#define ABSL_HAVE_ATTRIBUTE_NO_TAIL_CALL 0
#endif
+
// ABSL_ATTRIBUTE_WEAK
-// For weak functions
+//
+// Tags a function as weak for the purposes of compilation and linking.
#if ABSL_HAVE_ATTRIBUTE(weak) || (defined(__GNUC__) && !defined(__clang__))
#undef ABSL_ATTRIBUTE_WEAK
#define ABSL_ATTRIBUTE_WEAK __attribute__((weak))
@@ -132,9 +162,11 @@
#define ABSL_ATTRIBUTE_WEAK
#define ABSL_HAVE_ATTRIBUTE_WEAK 0
#endif
+
// ABSL_ATTRIBUTE_NONNULL
-// Tell the compiler either that a particular function parameter
-// should be a non-null pointer, or that all pointer arguments should
+//
+// Tells the compiler either (a) that a particular function parameter
+// should be a non-null pointer, or (b) that all pointer arguments should
// be non-null.
//
// Note: As the GCC manual states, "[s]ince non-static C++ methods
@@ -142,10 +174,13 @@
// should be counted from two, not one."
//
// Args are indexed starting at 1.
-// For non-static class member functions, the implicit "this" argument
-// is arg 1, and the first explicit argument is arg 2.
-// For static class member functions, there is no implicit "this", and
-// the first explicit argument is arg 1.
+//
+// For non-static class member functions, the implicit `this` argument
+// is arg 1, and the first explicit argument is arg 2. For static class member
+// functions, there is no implicit `this`, and the first explicit argument is
+// arg 1.
+//
+// Example:
//
// /* arg_a cannot be null, but arg_b can */
// void Function(void* arg_a, void* arg_b) ABSL_ATTRIBUTE_NONNULL(1);
@@ -171,8 +206,10 @@
#else
#define ABSL_ATTRIBUTE_NONNULL(...)
#endif
+
// ABSL_ATTRIBUTE_NORETURN
-// Tell the compiler that a given function never returns
+//
+// Tells the compiler that a given function never returns.
#if ABSL_HAVE_ATTRIBUTE(noreturn) || (defined(__GNUC__) && !defined(__clang__))
#define ABSL_ATTRIBUTE_NORETURN __attribute__((noreturn))
#elif defined(_MSC_VER)
@@ -180,8 +217,10 @@
#else
#define ABSL_ATTRIBUTE_NORETURN
#endif
+
// ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS
-// Tell AddressSanitizer (or other memory testing tools) to ignore a given
+//
+// Tells the AddressSanitizer (or other memory testing tools) to ignore a given
// function. Useful for cases when a function reads random locations on stack,
// calls _exit from a cloned subprocess, deliberately accesses buffer
// out of bounds or does other scary things with memory.
@@ -194,11 +233,12 @@
#endif
// ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY
-// Tell MemorySanitizer to relax the handling of a given function. All "Use of
-// uninitialized value" warnings from such functions will be suppressed, and all
-// values loaded from memory will be considered fully initialized.
-// This is similar to the ADDRESS_SANITIZER attribute above, but deals with
-// initializedness rather than addressability issues.
+//
+// Tells the MemorySanitizer to relax the handling of a given function. All
+// "Use of uninitialized value" warnings from such functions will be suppressed,
+// and all values loaded from memory will be considered fully initialized.
+// This attribute is similar to the ADDRESS_SANITIZER attribute above, but deals
+// with initialized-ness rather than addressability issues.
// NOTE: MemorySanitizer(msan) is supported by Clang but not GCC.
#if defined(__GNUC__) && defined(MEMORY_SANITIZER)
#define ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory))
@@ -207,8 +247,8 @@
#endif
// ABSL_ATTRIBUTE_NO_SANITIZE_THREAD
-// Tell ThreadSanitizer to not instrument a given function.
-// If you are adding this attribute, please cc dynamic-tools@ on the cl.
+//
+// Tells the ThreadSanitizer to not instrument a given function.
// NOTE: GCC supports ThreadSanitizer(tsan) since 4.8.
// https://gcc.gnu.org/gcc-4.8/changes.html
#if defined(__GNUC__) && defined(THREAD_SANITIZER)
@@ -218,7 +258,8 @@
#endif
// ABSL_ATTRIBUTE_NO_SANITIZE_UNDEFINED
-// Tell UndefinedSanitizer to ignore a given function. Useful for cases
+//
+// Tells the UndefinedSanitizer to ignore a given function. Useful for cases
// where certain behavior (eg. devision by zero) is being used intentionally.
// NOTE: GCC supports UndefinedBehaviorSanitizer(ubsan) since 4.9.
// https://gcc.gnu.org/gcc-4.9/changes.html
@@ -231,7 +272,8 @@
#endif
// ABSL_ATTRIBUTE_NO_SANITIZE_CFI
-// Tell ControlFlowIntegrity sanitizer to not instrument a given function.
+//
+// Tells the ControlFlowIntegrity sanitizer to not instrument a given function.
// See https://clang.llvm.org/docs/ControlFlowIntegrity.html for details.
#if defined(__GNUC__) && defined(CONTROL_FLOW_INTEGRITY)
#define ABSL_ATTRIBUTE_NO_SANITIZE_CFI __attribute__((no_sanitize("cfi")))
@@ -239,33 +281,42 @@
#define ABSL_ATTRIBUTE_NO_SANITIZE_CFI
#endif
-// ABSL_ATTRIBUTE_SECTION
-// Labeled sections are not supported on Darwin/iOS.
+// ABSL_HAVE_ATTRIBUTE_SECTION
+//
+// Indicates whether labeled sections are supported. Labeled sections are not
+// supported on Darwin/iOS.
#ifdef ABSL_HAVE_ATTRIBUTE_SECTION
#error ABSL_HAVE_ATTRIBUTE_SECTION cannot be directly set
#elif (ABSL_HAVE_ATTRIBUTE(section) || \
(defined(__GNUC__) && !defined(__clang__))) && \
!defined(__APPLE__)
#define ABSL_HAVE_ATTRIBUTE_SECTION 1
+
+// ABSL_ATTRIBUTE_SECTION
//
-// Tell the compiler/linker to put a given function into a section and define
-// "__start_ ## name" and "__stop_ ## name" symbols to bracket the section.
-// This functionality is supported by GNU linker.
-// Any function with ABSL_ATTRIBUTE_SECTION must not be inlined, or it will
-// be placed into whatever section its caller is placed into.
+// Tells the compiler/linker to put a given function into a section and define
+// `__start_ ## name` and `__stop_ ## name` symbols to bracket the section.
+// This functionality is supported by GNU linker. Any function annotated with
+// `ABSL_ATTRIBUTE_SECTION` must not be inlined, or it will be placed into
+// whatever section its caller is placed into.
//
#ifndef ABSL_ATTRIBUTE_SECTION
#define ABSL_ATTRIBUTE_SECTION(name) \
__attribute__((section(#name))) __attribute__((noinline))
#endif
-// Tell the compiler/linker to put a given variable into a section and define
-// "__start_ ## name" and "__stop_ ## name" symbols to bracket the section.
+
+// ABSL_ATTRIBUTE_SECTION_VARIABLE
+//
+// Tells the compiler/linker to put a given variable into a section and define
+// `__start_ ## name` and `__stop_ ## name` symbols to bracket the section.
// This functionality is supported by GNU linker.
#ifndef ABSL_ATTRIBUTE_SECTION_VARIABLE
#define ABSL_ATTRIBUTE_SECTION_VARIABLE(name) __attribute__((section(#name)))
#endif
+
+// ABSL_DECLARE_ATTRIBUTE_SECTION_VARS
//
-// Weak section declaration to be used as a global declaration
+// A weak section declaration to be used as a global declaration
// for ABSL_ATTRIBUTE_SECTION_START|STOP(name) to compile and link
// even without functions with ABSL_ATTRIBUTE_SECTION(name).
// ABSL_DEFINE_ATTRIBUTE_SECTION should be in the exactly one file; it's
@@ -281,7 +332,9 @@
#define ABSL_DEFINE_ATTRIBUTE_SECTION_VARS(name)
#endif
-// Return void* pointers to start/end of a section of code with
+// ABSL_ATTRIBUTE_SECTION_START
+//
+// Returns `void*` pointers to start/end of a section of code with
// functions having ABSL_ATTRIBUTE_SECTION(name).
// Returns 0 if no such functions exist.
// One must ABSL_DECLARE_ATTRIBUTE_SECTION_VARS(name) for this to compile and
@@ -306,6 +359,7 @@
#endif // ABSL_ATTRIBUTE_SECTION
// ABSL_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC
+//
// Support for aligning the stack on 32-bit x86.
#if ABSL_HAVE_ATTRIBUTE(force_align_arg_pointer) || \
(defined(__GNUC__) && !defined(__clang__))
@@ -326,10 +380,13 @@
#endif
// ABSL_MUST_USE_RESULT
-// Tell the compiler to warn about unused return values for functions declared
+//
+// Tells the compiler to warn about unused return values for functions declared
// with this macro. The macro must appear as the very first part of a function
// declaration or definition:
//
+// Example:
+//
// ABSL_MUST_USE_RESULT Sprocket* AllocateSprocket();
//
// This placement has the broadest compatibility with GCC, Clang, and MSVC, with
@@ -350,10 +407,14 @@
#endif
// ABSL_ATTRIBUTE_HOT, ABSL_ATTRIBUTE_COLD
-// Tell GCC that a function is hot or cold. GCC can use this information to
+//
+// Tells GCC that a function is hot or cold. GCC can use this information to
// improve static analysis, i.e. a conditional branch to a cold function
// is likely to be not-taken.
-// This annotation is used for function declarations, e.g.:
+// This annotation is used for function declarations.
+//
+// Example:
+//
// int foo() ABSL_ATTRIBUTE_HOT;
#if ABSL_HAVE_ATTRIBUTE(hot) || (defined(__GNUC__) && !defined(__clang__))
#define ABSL_ATTRIBUTE_HOT __attribute__((hot))
@@ -382,12 +443,12 @@
//
// These attributes only take effect when the following conditions are met:
//
-// - The file/target is built in at least C++11 mode, with a Clang compiler
-// that supports XRay attributes.
-// - The file/target is built with the -fxray-instrument flag set for the
-// Clang/LLVM compiler.
-// - The function is defined in the translation unit (the compiler honors the
-// attribute in either the definition or the declaration, and must match).
+// * The file/target is built in at least C++11 mode, with a Clang compiler
+// that supports XRay attributes.
+// * The file/target is built with the -fxray-instrument flag set for the
+// Clang/LLVM compiler.
+// * The function is defined in the translation unit (the compiler honors the
+// attribute in either the definition or the declaration, and must match).
//
// There are cases when, even when building with XRay instrumentation, users
// might want to control specifically which functions are instrumented for a
@@ -422,7 +483,8 @@
// -----------------------------------------------------------------------------
// ABSL_ATTRIBUTE_UNUSED
-// Prevent the compiler from complaining about or optimizing away variables
+//
+// Prevents the compiler from complaining about or optimizing away variables
// that appear unused.
#if ABSL_HAVE_ATTRIBUTE(unused) || (defined(__GNUC__) && !defined(__clang__))
#undef ABSL_ATTRIBUTE_UNUSED
@@ -430,8 +492,10 @@
#else
#define ABSL_ATTRIBUTE_UNUSED
#endif
+
// ABSL_ATTRIBUTE_INITIAL_EXEC
-// Tell the compiler to use "initial-exec" mode for a thread-local variable.
+//
+// Tells the compiler to use "initial-exec" mode for a thread-local variable.
// See http://people.redhat.com/drepper/tls.pdf for the gory details.
#if ABSL_HAVE_ATTRIBUTE(tls_model) || (defined(__GNUC__) && !defined(__clang__))
#define ABSL_ATTRIBUTE_INITIAL_EXEC __attribute__((tls_model("initial-exec")))
@@ -440,7 +504,8 @@
#endif
// ABSL_ATTRIBUTE_PACKED
-// Prevent the compiler from padding a structure to natural alignment
+//
+// Prevents the compiler from padding a structure to natural alignment
#if ABSL_HAVE_ATTRIBUTE(packed) || (defined(__GNUC__) && !defined(__clang__))
#define ABSL_ATTRIBUTE_PACKED __attribute__((__packed__))
#else
@@ -448,15 +513,16 @@
#endif
// ABSL_CONST_INIT
-// A variable declaration annotated with the ABSL_CONST_INIT attribute will
+//
+// A variable declaration annotated with the `ABSL_CONST_INIT` attribute will
// not compile (on supported platforms) unless the variable has a constant
// initializer. This is useful for variables with static and thread storage
// duration, because it guarantees that they will not suffer from the so-called
// "static init order fiasco".
//
-// Sample usage:
+// Example:
//
-// ABSL_CONST_INIT static MyType my_var = MakeMyType(...);
+// ABSL_CONST_INIT static MyType my_var = MakeMyType(...);
//
// Note that this attribute is redundant if the variable is declared constexpr.
#if ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization)
diff --git a/absl/base/call_once.h b/absl/base/call_once.h
index 478a41c1..5d823a11 100644
--- a/absl/base/call_once.h
+++ b/absl/base/call_once.h
@@ -25,6 +25,7 @@
#ifndef ABSL_BASE_CALL_ONCE_H_
#define ABSL_BASE_CALL_ONCE_H_
+#include <algorithm>
#include <atomic>
#include <cstdint>
#include <type_traits>
@@ -32,7 +33,10 @@
#include "absl/base/internal/invoke.h"
#include "absl/base/internal/low_level_scheduling.h"
#include "absl/base/internal/raw_logging.h"
+#include "absl/base/internal/scheduling_mode.h"
#include "absl/base/internal/spinlock_wait.h"
+#include "absl/base/macros.h"
+#include "absl/base/port.h"
namespace absl {
diff --git a/absl/base/call_once_test.cc b/absl/base/call_once_test.cc
index de235432..cd58ee19 100644
--- a/absl/base/call_once_test.cc
+++ b/absl/base/call_once_test.cc
@@ -14,12 +14,12 @@
#include "absl/base/call_once.h"
-#include <atomic>
#include <thread>
+#include <vector>
+#include "gtest/gtest.h"
#include "absl/base/thread_annotations.h"
#include "absl/synchronization/mutex.h"
-#include "gtest/gtest.h"
namespace absl {
namespace {
diff --git a/absl/base/config_test.cc b/absl/base/config_test.cc
index 578bb810..ab04b447 100644
--- a/absl/base/config_test.cc
+++ b/absl/base/config_test.cc
@@ -16,7 +16,6 @@
#include <cstdint>
-#include "gmock/gmock.h"
#include "gtest/gtest.h"
namespace {
diff --git a/absl/base/dynamic_annotations.h b/absl/base/dynamic_annotations.h
index b9c015ba..3b6d6ef4 100644
--- a/absl/base/dynamic_annotations.h
+++ b/absl/base/dynamic_annotations.h
@@ -298,7 +298,7 @@ void AnnotateIgnoreWritesEnd(const char *file, int line);
while still letting the compiler elide the functions from the final build.
TODO(delesley) -- The exclusive lock here ignores writes as well, but
- allows INGORE_READS_AND_WRITES to work properly. */
+ allows IGNORE_READS_AND_WRITES to work properly. */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
static inline void StaticAnnotateIgnoreReadsBegin(const char *file, int line)
diff --git a/absl/base/internal/atomic_hook.h b/absl/base/internal/atomic_hook.h
index 8eee367e..1f9a8102 100644
--- a/absl/base/internal/atomic_hook.h
+++ b/absl/base/internal/atomic_hook.h
@@ -16,8 +16,8 @@
#ifndef ABSL_BASE_INTERNAL_ATOMIC_HOOK_H_
#define ABSL_BASE_INTERNAL_ATOMIC_HOOK_H_
-#include <cassert>
#include <atomic>
+#include <cassert>
#include <utility>
namespace absl {
diff --git a/absl/base/internal/endian_test.cc b/absl/base/internal/endian_test.cc
index 6812214e..f3ff4b39 100644
--- a/absl/base/internal/endian_test.cc
+++ b/absl/base/internal/endian_test.cc
@@ -16,13 +16,11 @@
#include <algorithm>
#include <cstdint>
-#include <cstdio>
#include <limits>
#include <random>
#include <vector>
#include "gtest/gtest.h"
-#include "absl/base/casts.h"
#include "absl/base/config.h"
namespace absl {
diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index c55201b3..08f89ea9 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -17,17 +17,19 @@
// This allocator is slow and wasteful of memory;
// it should not be used when performance is key.
-#include "absl/base/config.h"
-
#include "absl/base/internal/low_level_alloc.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/scheduling_mode.h"
+#include "absl/base/macros.h"
+#include "absl/base/thread_annotations.h"
+
// LowLevelAlloc requires that the platform support low-level
// allocation of virtual memory. Platforms lacking this cannot use
// LowLevelAlloc.
#ifndef ABSL_LOW_LEVEL_ALLOC_MISSING
#ifndef _WIN32
-#include <pthread.h>
#include <signal.h>
#include <sys/mman.h>
#include <unistd.h>
@@ -38,8 +40,8 @@
#include <string.h>
#include <algorithm>
#include <atomic>
-#include <cstddef>
#include <cerrno>
+#include <cstddef>
#include <new> // for placement-new
#include "absl/base/dynamic_annotations.h"
diff --git a/absl/base/internal/low_level_alloc.h b/absl/base/internal/low_level_alloc.h
index d6eb813f..f3e8aa57 100644
--- a/absl/base/internal/low_level_alloc.h
+++ b/absl/base/internal/low_level_alloc.h
@@ -24,8 +24,10 @@
// IWYU pragma: private, include "base/low_level_alloc.h"
+#include <sys/types.h>
#include <cstdint>
+#include "absl/base/attributes.h"
#include "absl/base/config.h"
// LowLevelAlloc requires that the platform support low-level
diff --git a/absl/base/internal/low_level_alloc_test.cc b/absl/base/internal/low_level_alloc_test.cc
index 5f60c3d9..2935760d 100644
--- a/absl/base/internal/low_level_alloc_test.cc
+++ b/absl/base/internal/low_level_alloc_test.cc
@@ -14,10 +14,12 @@
#include "absl/base/internal/low_level_alloc.h"
+#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <thread> // NOLINT(build/c++11)
#include <unordered_map>
+#include <utility>
#include "absl/base/internal/malloc_hook.h"
diff --git a/absl/base/internal/low_level_scheduling.h b/absl/base/internal/low_level_scheduling.h
index b9501076..a01d1c03 100644
--- a/absl/base/internal/low_level_scheduling.h
+++ b/absl/base/internal/low_level_scheduling.h
@@ -30,8 +30,8 @@ extern "C" void __google_enable_rescheduling(bool disable_result);
namespace absl {
namespace base_internal {
-class SpinLock; // To allow use of SchedulingGuard.
class SchedulingHelper; // To allow use of SchedulingGuard.
+class SpinLock; // To allow use of SchedulingGuard.
// SchedulingGuard
// Provides guard semantics that may be used to disable cooperative rescheduling
diff --git a/absl/base/internal/malloc_extension.cc b/absl/base/internal/malloc_extension.cc
index daf4bc32..3da981ce 100644
--- a/absl/base/internal/malloc_extension.cc
+++ b/absl/base/internal/malloc_extension.cc
@@ -15,15 +15,12 @@
#include "absl/base/internal/malloc_extension.h"
#include <assert.h>
-#include <stdint.h>
-#include <stdio.h>
#include <string.h>
#include <atomic>
#include <string>
#include "absl/base/dynamic_annotations.h"
#include "absl/base/internal/malloc_extension_c.h"
-#include "absl/base/port.h"
namespace absl {
namespace base_internal {
diff --git a/absl/base/internal/malloc_extension.h b/absl/base/internal/malloc_extension.h
index dee4116b..46b767ff 100644
--- a/absl/base/internal/malloc_extension.h
+++ b/absl/base/internal/malloc_extension.h
@@ -25,14 +25,15 @@
#ifndef ABSL_BASE_INTERNAL_MALLOC_EXTENSION_H_
#define ABSL_BASE_INTERNAL_MALLOC_EXTENSION_H_
+#include <stddef.h>
+#include <stdint.h>
#include <atomic>
#include <map>
#include <memory>
+#include <string>
#include <vector>
-#include <stddef.h>
-#include <stdint.h>
-#include <string>
+#include "absl/base/attributes.h"
#include "absl/base/macros.h"
#include "absl/base/port.h"
namespace absl {
diff --git a/absl/base/internal/malloc_hook.cc b/absl/base/internal/malloc_hook.cc
index d5d227a5..4f5a0bef 100644
--- a/absl/base/internal/malloc_hook.cc
+++ b/absl/base/internal/malloc_hook.cc
@@ -23,16 +23,17 @@
#undef mremap
#endif
+#include "absl/base/internal/malloc_hook.h"
+
+#include <algorithm>
#include <cstddef>
#include <cstdint>
-#include <algorithm>
#include "absl/base/call_once.h"
-#include "absl/base/casts.h"
-#include "absl/base/internal/malloc_hook.h"
#include "absl/base/internal/malloc_hook_invoke.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/base/internal/spinlock.h"
+#include "absl/base/macros.h"
// __THROW is defined in glibc systems. It means, counter-intuitively,
// "This function will never throw an exception." It's an optional
diff --git a/absl/base/internal/raw_logging.cc b/absl/base/internal/raw_logging.cc
index d197d444..c0890614 100644
--- a/absl/base/internal/raw_logging.cc
+++ b/absl/base/internal/raw_logging.cc
@@ -12,8 +12,9 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-#include <atomic>
-#include <cassert>
+#include "absl/base/internal/raw_logging.h"
+
+#include <stddef.h>
#include <cstdarg>
#include <cstdio>
#include <cstdlib>
@@ -22,8 +23,6 @@
#include "absl/base/config.h"
#include "absl/base/internal/atomic_hook.h"
#include "absl/base/internal/log_severity.h"
-#include "absl/base/internal/raw_logging.h"
-#include "absl/base/port.h"
// We know how to perform low-level writes to stderr in POSIX and Windows. For
// these platforms, we define the token ABSL_LOW_LEVEL_WRITE_SUPPORTED.
@@ -38,6 +37,7 @@
#if defined(__linux__) || defined(__APPLE__) || defined(__Fuchsia__) || \
defined(__GENCLAVE__)
#include <unistd.h>
+
#define ABSL_HAVE_POSIX_WRITE 1
#define ABSL_LOW_LEVEL_WRITE_SUPPORTED 1
#else
@@ -57,6 +57,7 @@
#ifdef _WIN32
#include <io.h>
+
#define ABSL_HAVE_RAW_IO 1
#define ABSL_LOW_LEVEL_WRITE_SUPPORTED 1
#else
diff --git a/absl/base/internal/raw_logging.h b/absl/base/internal/raw_logging.h
index 47cf4373..568d2afc 100644
--- a/absl/base/internal/raw_logging.h
+++ b/absl/base/internal/raw_logging.h
@@ -19,6 +19,7 @@
#ifndef ABSL_BASE_INTERNAL_RAW_LOGGING_H_
#define ABSL_BASE_INTERNAL_RAW_LOGGING_H_
+#include "absl/base/attributes.h"
#include "absl/base/internal/log_severity.h"
#include "absl/base/macros.h"
#include "absl/base/port.h"
diff --git a/absl/base/internal/spinlock.cc b/absl/base/internal/spinlock.cc
index 6257bfce..517668dc 100644
--- a/absl/base/internal/spinlock.cc
+++ b/absl/base/internal/spinlock.cc
@@ -16,8 +16,8 @@
#include <algorithm>
#include <atomic>
+#include <limits>
-#include "absl/base/casts.h"
#include "absl/base/internal/atomic_hook.h"
#include "absl/base/internal/cycleclock.h"
#include "absl/base/internal/spinlock_wait.h"
diff --git a/absl/base/internal/spinlock.h b/absl/base/internal/spinlock.h
index fa64ba65..1f50d745 100644
--- a/absl/base/internal/spinlock.h
+++ b/absl/base/internal/spinlock.h
@@ -30,11 +30,17 @@
#ifndef ABSL_BASE_INTERNAL_SPINLOCK_H_
#define ABSL_BASE_INTERNAL_SPINLOCK_H_
+#include <stdint.h>
+#include <sys/types.h>
#include <atomic>
+#include "absl/base/attributes.h"
#include "absl/base/dynamic_annotations.h"
#include "absl/base/internal/low_level_scheduling.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/base/internal/scheduling_mode.h"
#include "absl/base/internal/tsan_mutex_interface.h"
+#include "absl/base/macros.h"
#include "absl/base/port.h"
#include "absl/base/thread_annotations.h"
diff --git a/absl/base/internal/spinlock_wait.h b/absl/base/internal/spinlock_wait.h
index 5432c1ce..6734cc9e 100644
--- a/absl/base/internal/spinlock_wait.h
+++ b/absl/base/internal/spinlock_wait.h
@@ -22,6 +22,7 @@
// places listing in //base:spinlock_wait_users. If you need to use it outside
// of //base, please request permission to be added to that list.
+#include <stdint.h>
#include <atomic>
#include "absl/base/internal/scheduling_mode.h"
diff --git a/absl/base/internal/sysinfo.cc b/absl/base/internal/sysinfo.cc
index 11863eab..6a4c0064 100644
--- a/absl/base/internal/sysinfo.cc
+++ b/absl/base/internal/sysinfo.cc
@@ -48,7 +48,6 @@
#include "absl/base/internal/raw_logging.h"
#include "absl/base/internal/spinlock.h"
#include "absl/base/internal/unscaledcycleclock.h"
-#include "absl/base/thread_annotations.h"
namespace absl {
namespace base_internal {
diff --git a/absl/base/internal/thread_identity_test.cc b/absl/base/internal/thread_identity_test.cc
index a2b053d9..7695a091 100644
--- a/absl/base/internal/thread_identity_test.cc
+++ b/absl/base/internal/thread_identity_test.cc
@@ -19,6 +19,7 @@
#include "gtest/gtest.h"
#include "absl/base/internal/spinlock.h"
+#include "absl/base/macros.h"
#include "absl/synchronization/internal/per_thread_sem.h"
#include "absl/synchronization/mutex.h"
diff --git a/absl/base/internal/unscaledcycleclock.h b/absl/base/internal/unscaledcycleclock.h
index ddf6a5e5..049f1cac 100644
--- a/absl/base/internal/unscaledcycleclock.h
+++ b/absl/base/internal/unscaledcycleclock.h
@@ -91,6 +91,7 @@ class UnscaledCycleClockWrapperForGetCurrentTime;
namespace base_internal {
class CycleClock;
class UnscaledCycleClockWrapperForInitializeFrequency;
+
class UnscaledCycleClock {
private:
UnscaledCycleClock() = delete;
diff --git a/absl/base/invoke_test.cc b/absl/base/invoke_test.cc
index 2bbfc477..466bf114 100644
--- a/absl/base/invoke_test.cc
+++ b/absl/base/invoke_test.cc
@@ -17,6 +17,7 @@
#include <functional>
#include <memory>
#include <string>
+#include <utility>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
diff --git a/absl/base/spinlock_test_common.cc b/absl/base/spinlock_test_common.cc
index b1212eaf..6918603c 100644
--- a/absl/base/spinlock_test_common.cc
+++ b/absl/base/spinlock_test_common.cc
@@ -24,8 +24,10 @@
#include "gtest/gtest.h"
#include "absl/base/internal/low_level_scheduling.h"
+#include "absl/base/internal/scheduling_mode.h"
#include "absl/base/internal/spinlock.h"
#include "absl/base/internal/sysinfo.h"
+#include "absl/base/macros.h"
#include "absl/synchronization/blocking_counter.h"
#include "absl/synchronization/notification.h"
diff --git a/absl/base/throw_delegate_test.cc b/absl/base/throw_delegate_test.cc
index f9494452..0f15df04 100644
--- a/absl/base/throw_delegate_test.cc
+++ b/absl/base/throw_delegate_test.cc
@@ -18,7 +18,6 @@
#include <new>
#include <stdexcept>
-#include "gmock/gmock.h"
#include "gtest/gtest.h"
namespace {
diff --git a/absl/numeric/int128.h b/absl/numeric/int128.h
index 72be806a..e3ba2384 100644
--- a/absl/numeric/int128.h
+++ b/absl/numeric/int128.h
@@ -78,10 +78,7 @@ namespace absl {
// uint64_t i = v // Error
// uint64_t i = static_cast<uint64_t>(v) // OK
//
-// NOTE: the alignment requirement of `uint128` is due to change, so users
-// should take care to avoid depending on the current 8 byte alignment.
-// TODO(strel) Remove alignment note above once alignof(uint128) becomes 16.
-class uint128 {
+class alignas(16) uint128 {
public:
uint128() = default;
diff --git a/absl/synchronization/BUILD.bazel b/absl/synchronization/BUILD.bazel
index bddd2eca..7efc67e6 100644
--- a/absl/synchronization/BUILD.bazel
+++ b/absl/synchronization/BUILD.bazel
@@ -80,6 +80,18 @@ cc_library(
)
cc_test(
+ name = "barrier_test",
+ size = "small",
+ srcs = ["barrier_test.cc"],
+ copts = ABSL_TEST_COPTS,
+ deps = [
+ ":synchronization",
+ "//absl/time",
+ "@com_google_googletest//:gtest_main",
+ ],
+)
+
+cc_test(
name = "blocking_counter_test",
size = "small",
srcs = ["blocking_counter_test.cc"],
diff --git a/absl/synchronization/barrier_test.cc b/absl/synchronization/barrier_test.cc
new file mode 100644
index 00000000..d6cababd
--- /dev/null
+++ b/absl/synchronization/barrier_test.cc
@@ -0,0 +1,75 @@
+// 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.
+
+#include "absl/synchronization/barrier.h"
+
+#include <thread> // NOLINT(build/c++11)
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "absl/synchronization/mutex.h"
+#include "absl/time/clock.h"
+
+
+TEST(Barrier, SanityTest) {
+ constexpr int kNumThreads = 10;
+ absl::Barrier* barrier = new absl::Barrier(kNumThreads);
+
+ absl::Mutex mutex;
+ int counter = 0; // Guarded by mutex.
+
+ auto thread_func = [&] {
+ if (barrier->Block()) {
+ // This thread is the last thread to reach the barrier so it is
+ // responsible for deleting it.
+ delete barrier;
+ }
+
+ // Increment the counter.
+ absl::MutexLock lock(&mutex);
+ ++counter;
+ };
+
+ // Start (kNumThreads - 1) threads running thread_func.
+ std::vector<std::thread> threads;
+ for (int i = 0; i < kNumThreads - 1; ++i) {
+ threads.push_back(std::thread(thread_func));
+ }
+
+ // Give (kNumThreads - 1) threads a chance to reach the barrier.
+ // This test assumes at least one thread will have run after the
+ // sleep has elapsed. Sleeping in a test is usually bad form, but we
+ // need to make sure that we are testing the barrier instead of some
+ // other synchronization method.
+ absl::SleepFor(absl::Seconds(1));
+
+ // The counter should still be zero since no thread should have
+ // been able to pass the barrier yet.
+ {
+ absl::MutexLock lock(&mutex);
+ EXPECT_EQ(counter, 0);
+ }
+
+ // Start 1 more thread. This should make all threads pass the barrier.
+ threads.push_back(std::thread(thread_func));
+
+ // All threads should now be able to proceed and finish.
+ for (auto& thread : threads) {
+ thread.join();
+ }
+
+ // All threads should now have incremented the counter.
+ absl::MutexLock lock(&mutex);
+ EXPECT_EQ(counter, kNumThreads);
+}
diff --git a/absl/time/duration_test.cc b/absl/time/duration_test.cc
index eed96e3e..ec8e17f5 100644
--- a/absl/time/duration_test.cc
+++ b/absl/time/duration_test.cc
@@ -1527,4 +1527,5 @@ TEST(Duration, FormatParseRoundTrip) {
#undef TEST_PARSE_ROUNDTRIP
}
+
} // namespace
diff --git a/absl/time/format_test.cc b/absl/time/format_test.cc
index cd9a6f9d..b139ff6f 100644
--- a/absl/time/format_test.cc
+++ b/absl/time/format_test.cc
@@ -427,4 +427,5 @@ TEST(FormatParse, RoundTripDistantPast) {
<< s << ": " << err;
EXPECT_EQ(in, out);
}
+
} // namespace
diff --git a/absl/types/optional.h b/absl/types/optional.h
index 5099d489..3e010bd5 100644
--- a/absl/types/optional.h
+++ b/absl/types/optional.h
@@ -439,6 +439,33 @@ struct is_constructible_convertible_assignable_from_optional
// for checking whether an expression is convertible to bool.
bool convertible_to_bool(bool);
+// Base class for std::hash<absl::optional<T>>:
+// If std::hash<std::remove_const_t<T>> is enabled, it provides operator() to
+// compute the hash; Otherwise, it is disabled.
+// Reference N4659 23.14.15 [unord.hash].
+template <typename T, typename = size_t>
+struct optional_hash_base {
+ optional_hash_base() = delete;
+ optional_hash_base(const optional_hash_base&) = delete;
+ optional_hash_base(optional_hash_base&&) = delete;
+ optional_hash_base& operator=(const optional_hash_base&) = delete;
+ optional_hash_base& operator=(optional_hash_base&&) = delete;
+};
+
+template <typename T>
+struct optional_hash_base<T, decltype(std::hash<absl::remove_const_t<T> >()(
+ std::declval<absl::remove_const_t<T> >()))> {
+ using argument_type = absl::optional<T>;
+ using result_type = size_t;
+ size_t operator()(const absl::optional<T>& opt) const {
+ if (opt) {
+ return std::hash<absl::remove_const_t<T> >()(*opt);
+ } else {
+ return static_cast<size_t>(0x297814aaad196e6dULL);
+ }
+ }
+};
+
} // namespace optional_internal
// -----------------------------------------------------------------------------
@@ -1072,15 +1099,8 @@ namespace std {
// std::hash specialization for absl::optional.
template <typename T>
-struct hash<absl::optional<T>> {
- size_t operator()(const absl::optional<T>& opt) const {
- if (opt) {
- return hash<T>()(*opt);
- } else {
- return static_cast<size_t>(0x297814aaad196e6dULL);
- }
- }
-};
+struct hash<absl::optional<T> >
+ : absl::optional_internal::optional_hash_base<T> {};
} // namespace std
diff --git a/absl/types/optional_test.cc b/absl/types/optional_test.cc
index 25b44b17..65f43871 100644
--- a/absl/types/optional_test.cc
+++ b/absl/types/optional_test.cc
@@ -24,6 +24,17 @@
#include "absl/meta/type_traits.h"
#include "absl/strings/string_view.h"
+struct Hashable {};
+
+namespace std {
+template <>
+struct hash<Hashable> {
+ size_t operator()(const Hashable&) { return 0; }
+};
+} // namespace std
+
+struct NonHashable {};
+
namespace {
std::string TypeQuals(std::string&) { return "&"; }
@@ -1434,6 +1445,17 @@ TEST(optionalTest, ValueType) {
(std::is_same<absl::optional<int>::value_type, absl::nullopt_t>::value));
}
+template <typename T>
+struct is_hash_enabled_for {
+ template <typename U, typename = decltype(std::hash<U>()(std::declval<U>()))>
+ static std::true_type test(int);
+
+ template <typename U>
+ static std::false_type test(...);
+
+ static constexpr bool value = decltype(test<T>(0))::value;
+};
+
TEST(optionalTest, Hash) {
std::hash<absl::optional<int>> hash;
std::set<size_t> hashcodes;
@@ -1442,6 +1464,34 @@ TEST(optionalTest, Hash) {
hashcodes.insert(hash(i));
}
EXPECT_GT(hashcodes.size(), 90);
+
+ static_assert(is_hash_enabled_for<absl::optional<int>>::value, "");
+ static_assert(is_hash_enabled_for<absl::optional<Hashable>>::value, "");
+
+#if defined(_MSC_VER) || (defined(_LIBCPP_VERSION) && \
+ _LIBCPP_VERSION < 4000 && _LIBCPP_STD_VER > 11)
+ // For MSVC and libc++ (< 4.0 and c++14), std::hash primary template has a
+ // static_assert to catch any user-defined type that doesn't provide a hash
+ // specialization. So instantiating std::hash<absl::optional<T>> will result
+ // in a hard error which is not SFINAE friendly.
+#define ABSL_STD_HASH_NOT_SFINAE_FRIENDLY 1
+#endif
+
+#ifndef ABSL_STD_HASH_NOT_SFINAE_FRIENDLY
+ static_assert(!is_hash_enabled_for<absl::optional<NonHashable>>::value, "");
+#endif
+
+ // libstdc++ std::optional is missing remove_const_t, i.e. it's using
+ // std::hash<T> rather than std::hash<std::remove_const_t<T>>.
+ // Reference: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82262
+#ifndef __GLIBCXX__
+ static_assert(is_hash_enabled_for<absl::optional<const int>>::value, "");
+ static_assert(is_hash_enabled_for<absl::optional<const Hashable>>::value, "");
+ std::hash<absl::optional<const int>> c_hash;
+ for (int i = 0; i < 100; ++i) {
+ EXPECT_EQ(hash(i), c_hash(i));
+ }
+#endif
}
struct MoveMeNoThrow {
diff --git a/absl/utility/utility.h b/absl/utility/utility.h
index 4f4a0624..732cd4c5 100644
--- a/absl/utility/utility.h
+++ b/absl/utility/utility.h
@@ -12,36 +12,39 @@
// See the License for the specific language governing permissions and
// limitations under the License.
//
-
-// absl/utility:utility is an extension of the <utility> header
+// This header file contains C++11 versions of standard <utility> header
+// abstractions available within C++14 and C++17, and are designed to be drop-in
+// replacement for code compliant with C++14 and C++17.
+//
+// The following abstractions are defined:
//
-// It provides stand-ins for C++14's std::integer_sequence and
-// related utilities. They are intended to be exactly equivalent.
-// - integer_sequence<T, Ints...> == std::integer_sequence<T, Ints...>
-// - index_sequence<Ints...> == std::index_sequence<Ints...>
-// - make_integer_sequence<T, N> == std::make_integer_sequence<T, N>
-// - make_index_sequence<N> == std::make_index_sequence<N>
-// - index_sequence_for<Ts...> == std::index_sequence_for<Ts...>
+// * integer_sequence<T, Ints...> == std::integer_sequence<T, Ints...>
+// * index_sequence<Ints...> == std::index_sequence<Ints...>
+// * make_integer_sequence<T, N> == std::make_integer_sequence<T, N>
+// * make_index_sequence<N> == std::make_index_sequence<N>
+// * index_sequence_for<Ts...> == std::index_sequence_for<Ts...>
//
-// It also provides the tag types in_place_t, in_place_type_t, and
-// in_place_index_t, as well as the constant in_place, and constexpr std::move
-// and std::forward impolementations in C++11.
+// This header file also provides the tag types `in_place_t`, `in_place_type_t`,
+// and `in_place_index_t`, as well as the constant `in_place`, and
+// `constexpr` `std::move()` and `std::forward()` implementations in C++11.
//
// References:
+//
// http://en.cppreference.com/w/cpp/utility/integer_sequence
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3658.html
//
+//
// Example:
// // Unpack a tuple for use as a function call's argument list.
//
// template <typename F, typename Tup, size_t... Is>
-// auto Impl(F f, const Tup& tup, index_sequence<Is...>)
+// auto Impl(F f, const Tup& tup, absl::index_sequence<Is...>)
// -> decltype(f(std::get<Is>(tup) ...)) {
// return f(std::get<Is>(tup) ...);
// }
//
// template <typename Tup>
-// using TupIdxSeq = make_index_sequence<std::tuple_size<Tup>::value>;
+// using TupIdxSeq = absl::make_index_sequence<std::tuple_size<Tup>::value>;
//
// template <typename F, typename Tup>
// auto ApplyFromTuple(F f, const Tup& tup)
@@ -60,23 +63,36 @@
namespace absl {
-// Equivalent to std::integer_sequence.
+// integer_sequence
+//
+// Class template representing a compile-time integer sequence. An instantiation
+// of `integer_sequence<T, Ints...>` has a sequence of integers encoded in its
+// type through its template arguments (which is a common need when
+// working with C++11 variadic templates). `absl::integer_sequence` is designed
+// to be a drop-in replacement for C++14's `std::integer_sequence`.
+//
+// Example:
//
-// Function templates can deduce compile-time integer sequences by accepting
-// an argument of integer_sequence<T, Ints...>. This is a common need when
-// working with C++11 variadic templates.
+// template< class T, T... Ints >
+// void user_function(integer_sequence<T, Ints...>);
//
-// T - the integer type of the sequence elements
-// ...Ints - a parameter pack of T values representing the sequence
+// int main()
+// {
+// // user_function's `T` will be deduced to `int` and `Ints...`
+// // will be deduced to `0, 1, 2, 3, 4`.
+// user_function(make_integer_sequence<int, 5>());
+// }
template <typename T, T... Ints>
struct integer_sequence {
using value_type = T;
static constexpr size_t size() noexcept { return sizeof...(Ints); }
};
-// Equivalent to std::index_sequence.
+// index_sequence
//
-// Alias for an integer_sequence of size_t.
+// A helper template for an `integer_sequence` of `size_t`,
+// `absl::index_sequence` is designed to be a drop-in replacement for C++14's
+// `std::index_sequence`.
template <size_t... Ints>
using index_sequence = integer_sequence<size_t, Ints...>;
@@ -113,21 +129,27 @@ struct Gen<T, 0> {
// Compile-time sequences of integers
-// Equivalent to std::make_integer_sequence.
+// make_integer_sequence
//
-// make_integer_sequence<int, N> is integer_sequence<int, 0, 1, ..., N-1>;
+// This template alias is equivalent to
+// `integer_sequence<int, 0, 1, ..., N-1>`, and is designed to be a drop-in
+// replacement for C++14's `std::make_integer_sequence`.
template <typename T, T N>
using make_integer_sequence = typename utility_internal::Gen<T, N>::type;
-// Equivalent to std::make_index_sequence.
+// make_index_sequence
//
-// make_index_sequence<N> is index_sequence<0, 1, ..., N-1>;
+// This template alias is equivalent to `index_sequence<0, 1, ..., N-1>`,
+// and is designed to be a drop-in replacement for C++14's
+// `std::make_index_sequence`.
template <size_t N>
using make_index_sequence = make_integer_sequence<size_t, N>;
-// Equivalent to std::index_sequence_for.
+// index_sequence_for
//
-// Convert a typename pack into an index sequence of the same length.
+// Converts a typename pack into an index sequence of the same length, and
+// is designed to be a drop-in replacement for C++14's
+// `std::index_sequence_for()`
template <typename... Ts>
using index_sequence_for = make_index_sequence<sizeof...(Ts)>;
@@ -140,8 +162,11 @@ using std::in_place;
#else // ABSL_HAVE_STD_OPTIONAL
-// Tag type used in order to specify in-place construction, such as with
-// absl::optional.
+// in_place_t
+//
+// Tag type used to specify in-place construction, such as with
+// `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;
@@ -150,22 +175,39 @@ extern const in_place_t in_place;
#ifdef ABSL_HAVE_STD_ANY
using std::in_place_type_t;
#else
-// Tag types used for in-place construction when the type to construct needs to
-// be specified, such as with absl::variant and absl::any.
+
+// in_place_type_t
+//
+// Tag type used for in-place construction when the type to construct needs to
+// be specified, such as with `absl::any`, designed to be a drop-in replacement
+// for C++17's `std::in_place_type_t`.
template <typename T>
struct in_place_type_t {};
#endif // ABSL_HAVE_STD_ANY
+// in_place_index_t
+//
+// Tag type used for in-place construction when the type to construct needs to
+// be specified, such as with `absl::any`, designed to be a drop-in replacement
+// for C++17's `std::in_place_index_t`.
template <size_t I>
struct in_place_index_t {};
// Constexpr move and forward
+// move()
+//
+// A constexpr version of `std::move()`, designed to be a drop-in replacement
+// for C++14's `std::move()`.
template <typename T>
constexpr absl::remove_reference_t<T>&& move(T&& t) noexcept {
return static_cast<absl::remove_reference_t<T>&&>(t);
}
+// forward()
+//
+// A constexpr version of `std::forward()`, designed to be a drop-in replacement
+// for C++14's `std::forward()`.
template <typename T>
constexpr T&& forward(
absl::remove_reference_t<T>& t) noexcept { // NOLINT(runtime/references)