summaryrefslogtreecommitdiff
path: root/absl/functional
diff options
context:
space:
mode:
authorGravatar Abseil Team <absl-team@google.com>2020-02-21 12:51:36 -0800
committerGravatar CJ Johnson <johnsoncj@google.com>2020-02-21 15:56:04 -0500
commitb69c7d880caddfc25bf348dbcfe9d45fdd8bc6e6 (patch)
tree0ceef2d75071fdfdf7a47c2978a4df5b422001ed /absl/functional
parent2a5633fc077a58528cdbfe78720f3f6bfdc6044d (diff)
Export of internal Abseil changes
-- 00f5301405423005d9129935c05f20155536cc1a by CJ Johnson <johnsoncj@google.com>: Removes usage of std::aligned_storage from Abseil implementation details PiperOrigin-RevId: 296492301 -- fc11d15f91764612fba080669d2381dc181df52b by Abseil Team <absl-team@google.com>: Fix absl::bind_front documentation. PiperOrigin-RevId: 296482945 -- 0164c595c129c46bf21ae74eba5399a1da5f140b by Gennadiy Rozental <rogeeff@google.com>: Automated g4 rollback of changelist 296320700. PiperOrigin-RevId: 296439968 -- 1eb295700758ca0894d872b2de7c675b4ad679af by Abseil Team <absl-team@google.com>: Removes duplicate comments. PiperOrigin-RevId: 296433214 -- c30c01caae02d2fa4ef783d988de6bebb9757c39 by Derek Mauro <dmauro@google.com>: Merge GitHub #621: Add RISCV support to GetProgramCounter() Fixes #621 PiperOrigin-RevId: 296351174 -- 95d4498167596fd7543e025bdfe9a8da9e2ca3c8 by Abseil Team <absl-team@google.com>: Automated g4 rollback of changelist 296320700. PiperOrigin-RevId: 296348701 -- b193f0543e0cec54dddb2ed51f45dc489c8d06d5 by Gennadiy Rozental <rogeeff@google.com>: Change TryParse interface to return managed value. In addition introduce companion StoreValue routine which consumes pointer to source value and stores the value inside of FlagImpl. In a follow up CL we will change StoreValue implementation to behave differently depending on "value storage kind". We also rename default_src_ to default_value_. PiperOrigin-RevId: 296320700 -- 57e942b485d12912a0a8d0d0b35fa2a62847020f by Derek Mauro <dmauro@google.com>: Merge GitHub #622 * Add missing #ifdef conditionals for ABSL_HAVE_VDSO_SUPPORT PiperOrigin-RevId: 296272830 GitOrigin-RevId: 00f5301405423005d9129935c05f20155536cc1a Change-Id: I1b05eeaf1280f95fb0a2c5f3654995a87c792893
Diffstat (limited to 'absl/functional')
-rw-r--r--absl/functional/bind_front.h26
1 files changed, 22 insertions, 4 deletions
diff --git a/absl/functional/bind_front.h b/absl/functional/bind_front.h
index 8448d7b3..5b47970e 100644
--- a/absl/functional/bind_front.h
+++ b/absl/functional/bind_front.h
@@ -38,9 +38,7 @@ ABSL_NAMESPACE_BEGIN
// bind_front()
//
-// Binds the first N arguments of an invocable object and stores them by value,
-// except types of `std::reference_wrapper` which are 'unwound' and stored by
-// reference.
+// Binds the first N arguments of an invocable object and stores them by value.
//
// Like `std::bind()`, `absl::bind_front()` is implicitly convertible to
// `std::function`. In particular, it may be used as a simpler replacement for
@@ -140,7 +138,9 @@ ABSL_NAMESPACE_BEGIN
//
// Example: Storing bound arguments by reference.
//
-// void Print(const string& a, const string& b) { LOG(INFO) << a << b; }
+// void Print(const std::string& a, const std::string& b) {
+// std::cerr << a << b;
+// }
//
// std::string hi = "Hello, ";
// std::vector<std::string> names = {"Chuk", "Gek"};
@@ -152,6 +152,24 @@ ABSL_NAMESPACE_BEGIN
// // dangling references.
// foo->DoInFuture(absl::bind_front(Print, std::ref(hi), "Guest")); // BAD!
// auto f = absl::bind_front(Print, std::ref(hi), "Guest"); // BAD!
+//
+// Example: Storing reference-like types.
+//
+// void Print(absl::string_view a, const std::string& b) {
+// std::cerr << a << b;
+// }
+//
+// std::string hi = "Hello, ";
+// // Copies "hi".
+// absl::bind_front(Print, hi)("Chuk");
+//
+// // Compile error: std::reference_wrapper<const string> is not implicitly
+// // convertible to string_view.
+// // absl::bind_front(Print, std::cref(hi))("Chuk");
+//
+// // Doesn't copy "hi".
+// absl::bind_front(Print, absl::string_view(hi))("Chuk");
+//
template <class F, class... BoundArgs>
constexpr functional_internal::bind_front_t<F, BoundArgs...> bind_front(
F&& func, BoundArgs&&... args) {