adding a std::execution concurrency test to the playground

playground/CMakeLists.txt

@@ -10,6 +10,7 @@ set(REAL_SRCS efunc_posits.cpp
 	 type_test.cpp
 	 float_to_decimal_string.cpp
 	 lazy_evaluation.cpp
+	 concurrency.cpp
 	 expression_templates.cpp
 )
 

playground/concurrency.cpp

@@ -0,0 +1,50 @@
+// https://en.cppreference.com/w/cpp/algorithm/execution_policy_tag
+
+#include <algorithm>
+#include <chrono>
+#include <cstdint>
+#include <iostream>
+#include <random>
+#include <vector>
+
+#define PARALLEL
+#ifdef PARALLEL
+#include <execution>
+    namespace execution = std::execution;
+#else
+    enum class execution { seq, unseq, par_unseq, par };
+#endif
+
+void measure([[maybe_unused]] auto policy, std::vector<std::uint64_t> v)
+{
+    const auto start = std::chrono::steady_clock::now();
+#ifdef PARALLEL
+    std::sort(policy, v.begin(), v.end());
+#else
+    std::sort(v.begin(), v.end());
+#endif
+    const auto finish = std::chrono::steady_clock::now();
+    std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(finish - start)
+              << '\n';
+};
+
+int main()
+{
+    std::vector<std::uint64_t> v(1'000'000);
+    std::mt19937 gen {std::random_device{}()};
+    std::ranges::generate(v, gen);
+ /*
+  1M random uint64_t's 
+
+    83ms
+    74ms
+    12ms
+    12ms
+
+  on an 8 core machine
+ */
+    measure(execution::seq, v);
+    measure(execution::unseq, v);
+    measure(execution::par_unseq, v);
+    measure(execution::par, v);
+}