Adding upstream version 1.8.3.upstream/1.8.3

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

1 files changed, 67 insertions, 0 deletions

diff --git a/noinitvector.hh b/noinitvector.hh
new file mode 100644
index 0000000..cc7efc3
--- /dev/null
+++ b/noinitvector.hh
@@ -0,0 +1,67 @@
+#pragma once
+
+#include <memory>
+#include <new>
+#include <utility>
+#include <vector>
+
+// based on boost::core::noinit_adaptor
+// The goal is to avoid initialization of the content of a container,
+// because setting several kB of uint8_t to 0 has a real cost if you
+// do 100k times per second.
+template<class Allocator>
+struct noinit_adaptor: Allocator
+{
+  template<class U>
+  struct rebind {
+    typedef noinit_adaptor<typename std::allocator_traits<Allocator>::template
+                           rebind_alloc<U> > other;
+    };
+
+  noinit_adaptor(): Allocator() { }
+
+  template<class U>
+  noinit_adaptor(U&& u) noexcept : Allocator(std::forward<U>(u)) { }
+
+  template<class U>
+  noinit_adaptor(const noinit_adaptor<U>& u) noexcept : Allocator(static_cast<const U&>(u)) { }
+
+  template<class U>
+  void construct(U* p) {
+    ::new((void*)p) U;
+  }
+
+  template<class U, class V, class... Args>
+  void construct(U* p, V&& v, Args&&... args) {
+    ::new((void*)p) U(std::forward<V>(v), std::forward<Args>(args)...);
+  }
+
+  template<class U>
+  void destroy(U* p) {
+    p->~U();
+  }
+};
+
+template<class T, class U>
+inline bool operator==(const noinit_adaptor<T>& lhs,
+                       const noinit_adaptor<U>& rhs) noexcept
+{
+  return static_cast<const T&>(lhs) == static_cast<const U&>(rhs);
+}
+
+template<class T, class U>
+inline bool operator!=(const noinit_adaptor<T>& lhs,
+                       const noinit_adaptor<U>& rhs) noexcept
+{
+  return !(lhs == rhs);
+}
+
+template<class Allocator>
+inline noinit_adaptor<Allocator> noinit_adapt(const Allocator& a) noexcept
+{
+  return noinit_adaptor<Allocator>(a);
+}
+
+template<class T> using NoInitVector = std::vector<T, noinit_adaptor<std::allocator<T>>>;
+
+using PacketBuffer = NoInitVector<uint8_t>;