use benchpress for benchmark

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "vendor/spec"]
 	path = vendor/spec
 	url = https://github.com/mustache/spec.git
+[submodule "vendor/benchpress"]
+	path = vendor/benchpress
+	url = https://github.com/bigdatadev/benchpress.git

CMakeLists.txt

@@ -18,6 +18,7 @@ if(WITH_UNIT_TESTS)
   enable_testing()
   include_directories(
       vendor/Catch/single_include
-      vendor/json.hpp/include)
+      vendor/json.hpp/include
+      vendor/benchpress/src/benchpress)
   add_subdirectory(test)
 endif()

test/benchmark_main.cpp

@@ -1,14 +1,10 @@
+#define BENCHPRESS_CONFIG_MAIN
+
+#include <benchpress.hpp>
+
 #include "mstch/mstch.hpp"
 
-#include <chrono>
-#include <iostream>
-
-unsigned long long current_msec() {
-  return std::chrono::time_point_cast<std::chrono::milliseconds>(
-      std::chrono::system_clock::now()).time_since_epoch().count();
-}
-
-int main() {
+benchpress::auto_register basic_usage("basic usage", [](benchpress::context* ctx) {
     std::string comment_tmp{
         "<div class=\"comments\"><h3>{{header}}</h3><ul>"
         "{{#comments}}<li class=\"comment\"><h5>{{name}}</h5>"
@@ -21,24 +17,10 @@ int main() {
                 mstch::map{{"name", std::string{"Sam"}}, {"body", std::string{"Thanks for this post!"}}},
                 mstch::map{{"name", std::string{"Heather"}}, {"body", std::string{"Thanks for this post!"}}},
                 mstch::map{{"name", std::string{"Kathy"}}, {"body", std::string{"Thanks for this post!"}}},
-          mstch::map{{"name", std::string{"George"}}, {"body", std::string{"Thanks for this post!"}}}
-      }}
-  };
+                mstch::map{{"name", std::string{"George"}}, {"body", std::string{"Thanks for this post!"}}}}}};
 
-  std::vector<unsigned long long> times;
-  for (int j = 0; j < 10; j++) {
-    auto start = current_msec();
-    for (int i = 0; i < 5000; i++)
+    ctx->reset_timer();
+
+    for (size_t i = 0; i < ctx->num_iterations(); ++i)
         mstch::render(comment_tmp, comment_view);
-    times.push_back(current_msec() - start);
-  }
-
-  float avg = 0;
-  for (auto i: times)
-    avg += i;
-  avg /= times.size();
-
-  std::cout << avg << std::endl;
-
-  return 0;
-}
+});

vendor/benchpress

@@ -0,0 +1 @@
+Subproject commit 469b7c6b0b582389fa397d9b990a0ff1c3b93462