merge(3p/immer): Subtree merge at 'ad3e3556d' as 'third_party/immer'

Change-Id: I9636a41ad44b4218293833fd3e9456d9b07c731b

third_party/immer/benchmark/vector/push_front.hpp

@@ -0,0 +1,46 @@
+//
+// immer: immutable data structures for C++
+// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente
+//
+// This software is distributed under the Boost Software License, Version 1.0.
+// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt
+//
+
+#pragma once
+
+#include "benchmark/vector/common.hpp"
+
+namespace {
+
+template <typename Vektor>
+auto bechmark_push_front()
+{
+    return [] (nonius::chronometer meter)
+    {
+        auto n = meter.param<N>();
+
+        measure(meter, [&] {
+            auto v = Vektor{};
+            for (auto i = 0u; i < n; ++i)
+                v = v.push_front(i);
+            return v;
+        });
+    };
+}
+
+auto benchmark_push_front_librrb(nonius::chronometer meter)
+{
+    auto n = meter.param<N>();
+
+    measure(meter, [&] {
+        auto v = rrb_create();
+        for (auto i = 0u; i < n; ++i) {
+            auto f = rrb_push(rrb_create(),
+                              reinterpret_cast<void*>(i));
+            v = rrb_concat(f, v);
+        }
+        return v;
+    });
+}
+
+} // anonymous namespace