Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/crimson/common/utility.h b/src/crimson/common/utility.h
new file mode 100644
index 000000000..86b308155
--- /dev/null
+++ b/src/crimson/common/utility.h
@@ -0,0 +1,38 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:nil -*-
+// vim: ts=8 sw=2 smarttab expandtab
+
+#pragma once
+
+#include <type_traits>
+
+namespace _impl {
+  template <class T> struct always_false : std::false_type {};
+};
+
+template <class T>
+void assert_moveable(T& t) {
+    // It's fine
+}
+template <class T>
+void assert_moveable(const T& t) {
+    static_assert(_impl::always_false<T>::value, "unable to move-out from T");
+}
+
+namespace internal {
+
+template <typename Obj, typename Method, typename ArgTuple, size_t... I>
+static auto _apply_method_to_tuple(
+  Obj &obj, Method method, ArgTuple &&tuple,
+  std::index_sequence<I...>) {
+  return (obj.*method)(std::get<I>(std::forward<ArgTuple>(tuple))...);
+}
+
+}
+
+template <typename Obj, typename Method, typename ArgTuple>
+auto apply_method_to_tuple(Obj &obj, Method method, ArgTuple &&tuple) {
+  constexpr auto tuple_size = std::tuple_size_v<ArgTuple>;
+  return internal::_apply_method_to_tuple(
+    obj, method, std::forward<ArgTuple>(tuple),
+    std::make_index_sequence<tuple_size>());
+}