diff --git a/CMakeLists.txt b/CMakeLists.txt
index 16c7756..9b67727 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -143,6 +143,7 @@ if (PHMAP_BUILD_EXAMPLES)
     add_executable(ex_knucleotide examples/knucleotide.cc phmap.natvis)
     add_executable(ex_dump_load examples/dump_load.cc phmap.natvis)
     add_executable(ex_btree examples/btree.cc phmap.natvis)
+    add_executable(ex_matt examples/matt.cc phmap.natvis)
 
     target_link_libraries(ex_knucleotide Threads::Threads)
     target_link_libraries(ex_bench Threads::Threads)
diff --git a/examples/matt.cc b/examples/matt.cc
new file mode 100644
index 0000000..e9344ed
--- /dev/null
+++ b/examples/matt.cc
@@ -0,0 +1,99 @@
+#include <chrono>
+#include <ctime>
+#include <cstring>
+#include <cstdlib>
+#include <cstdio>
+#include <cmath>
+#include <vector>
+#include <random>
+#include <parallel_hashmap/phmap.h>
+
+// -------------------------------------------------------------------
+// -------------------------------------------------------------------
+class Timer
+{
+public:
+    Timer(std::string name) : _name(name), _start(std::chrono::high_resolution_clock::now()) {}
+
+    ~Timer() 
+    {
+        std::chrono::duration<float> elapsed_seconds = std::chrono::high_resolution_clock::now() - _start;
+        printf("%s: %.3fs\n", _name.c_str(), elapsed_seconds.count());
+    }
+
+private:
+    std::string _name;
+    std::chrono::high_resolution_clock::time_point _start;
+};
+
+// --------------------------------------------------------------------------
+//  from: https://github.com/preshing/RandomSequence
+// --------------------------------------------------------------------------
+class RSU
+{
+private:
+    uint32_t m_index;
+    uint32_t m_intermediateOffset;
+
+    static uint32_t permuteQPR(uint32_t x)
+    {
+        static const uint32_t prime = 4294967291u;
+        if (x >= prime)
+            return x;  // The 5 integers out of range are mapped to themselves.
+        uint32_t residue = ((unsigned long long) x * x) % prime;
+        return (x <= prime / 2) ? residue : prime - residue;
+    }
+
+public:
+    RSU(uint32_t seedBase, uint32_t seedOffset)
+    {
+        m_index = permuteQPR(permuteQPR(seedBase) + 0x682f0161);
+        m_intermediateOffset = permuteQPR(permuteQPR(seedOffset) + 0x46790905);
+    }
+
+    uint32_t next()
+    {
+        return permuteQPR((permuteQPR(m_index++) + m_intermediateOffset) ^ 0x5bf03635);
+    }
+};
+
+// --------------------------------------------------------------------------
+// --------------------------------------------------------------------------
+template<class Set, size_t N>
+void test(const char *name, std::function<void (std::vector<uint64_t> &)> perturb)
+{
+    Set s;
+
+    unsigned int seed = 76687;
+	RSU rsu(seed, seed + 1);
+
+    for (uint32_t i=0; i<N; ++i)
+        s.insert(rsu.next());
+
+    std::vector<uint64_t> order(s.begin(), s.end());
+    perturb(order);
+    order.resize(N/4);
+
+    Timer t(name);
+    Set c(order.begin(), order.end());
+}
+
+// --------------------------------------------------------------------------
+// --------------------------------------------------------------------------
+int main()
+{
+    auto shuffle = [](std::vector<uint64_t> &order) { 
+        std::random_device rd;
+        std::mt19937 g(rd());
+        std::shuffle(order.begin(), order.end(), g); 
+    };
+
+    test<phmap::flat_hash_set<uint64_t>, 10000000>("ordered", 
+                                                   [](std::vector<uint64_t> &) {});
+
+    test<phmap::flat_hash_set<uint64_t>, 10000000>("shuffled", shuffle);
+}
+    
+    
+    
+