Use C++20 standard for time management

Author: Grufoony

src/dsf/headers/Dynamics.hpp

@@ -13,6 +13,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <chrono>
 #include <concepts>
 #include <vector>
 #include <random>
@@ -28,7 +29,6 @@
 #include <filesystem>
 #include <functional>
 #include <iomanip>
-#include <sstream>
 
 #include <tbb/tbb.h>
 
@@ -97,10 +97,9 @@ namespace dsf {
     /// @brief Get the current simulation time as formatted string (YYYY-MM-DD HH:MM:SS)
     /// @return std::string, The current simulation time as formatted string
     inline auto strDateTime() const {
-      std::time_t const t = time();
-      std::ostringstream oss;
-      oss << std::put_time(std::localtime(&t), "%Y-%m-%d %H:%M:%S");
-      return oss.str();
+      return std::format(
+          "{:%Y-%m-%d %H:%M:%S}", std::chrono::floor<std::chrono::seconds>(std::chrono::current_zone()->to_local(
+                                      std::chrono::system_clock::from_time_t(time()))));
     }
   };
 

test/Test_dynamics.cpp

@@ -225,10 +225,11 @@ TEST_CASE("FirstOrderDynamics") {
       graph.importMatrix("./data/matrix.dat", false);
       // graph.adjustNodeCapacities();
       FirstOrderDynamics dynamics{graph, false, 69, 0., dsf::PathWeight::LENGTH};
-      std::ostringstream default_oss;
-      std::time_t defaultTime{0};
-      default_oss << std::put_time(std::localtime(&defaultTime), "%Y-%m-%d %H:%M:%S");
-      CHECK_EQ(dynamics.strDateTime(), default_oss.str());
+      CHECK_EQ(dynamics.strDateTime(),
+               std::format("{:%Y-%m-%d %H:%M:%S}",
+                           std::chrono::floor<std::chrono::seconds>(
+                               std::chrono::current_zone()->to_local(
+                                   std::chrono::system_clock::from_time_t(0)))));
       auto const epochStart{
           std::chrono::system_clock::to_time_t(std::chrono::system_clock::now())};
       dynamics.setInitTime(epochStart);
@@ -243,10 +244,13 @@ TEST_CASE("FirstOrderDynamics") {
           CHECK(dynamics.nAgents() < n);
           CHECK_EQ(dynamics.time_step(), 40);
           CHECK_EQ(dynamics.time() - epochStart, 40);
-          std::ostringstream oss;
-          auto currentTime = epochStart + 40;
-          oss << std::put_time(std::localtime(&currentTime), "%Y-%m-%d %H:%M:%S");
-          CHECK_EQ(dynamics.strDateTime(), oss.str());
+          CHECK_EQ(
+              dynamics.strDateTime(),
+              std::format(
+                  "{:%Y-%m-%d %H:%M:%S}",
+                  std::chrono::floor<std::chrono::seconds>(
+                      std::chrono::current_zone()->to_local(
+                          std::chrono::system_clock::from_time_t(dynamics.time())))));
         }
       }
     }