merge(3p/immer): Subtree merge at 'ad3e3556d' as 'third_party/immer' r/1299

Change-Id: I9636a41ad44b4218293833fd3e9456d9b07c731b

1 files changed, 44 insertions, 0 deletions

diff --git a/third_party/immer/benchmark/set/string-long/generator.ipp b/third_party/immer/benchmark/set/string-long/generator.ipp
new file mode 100644
index 000000000000..386364cc96fe
--- /dev/null
+++ b/third_party/immer/benchmark/set/string-long/generator.ipp
@@ -0,0 +1,44 @@
+//
+// 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
+//
+
+#include <random>
+#include <vector>
+#include <cassert>
+#include <functional>
+#include <algorithm>
+
+#define GENERATOR_T generate_unsigned
+
+namespace {
+
+struct GENERATOR_T
+{
+    static constexpr auto char_set   = "_-0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    static constexpr auto max_length = 256;
+    static constexpr auto min_length = 32;
+
+    auto operator() (std::size_t runs) const
+    {
+        assert(runs > 0);
+        auto engine = std::default_random_engine{42};
+        auto dist = std::uniform_int_distribution<unsigned>{};
+        auto gen = std::bind(dist, engine);
+        auto r = std::vector<std::string>(runs);
+        std::generate_n(r.begin(), runs, [&] {
+            auto len = gen() % (max_length - min_length) + min_length;
+            auto str = std::string(len, ' ');
+            std::generate_n(str.begin(), len, [&] {
+                return char_set[gen() % sizeof(char_set)];
+            });
+            return str;
+        });
+        return r;
+    }
+};
+
+} // namespace