From fe08e1f98914ddcbc57d1ebc449fcad0f34d82ae Mon Sep 17 00:00:00 2001
From: Marco Satti <msatti@metrol.co.uk>
Date: Thu, 19 Mar 2026 11:25:36 +0000
Subject: [PATCH 1/3] Add in post callback function to simulation

---
 include/fschuetz04/simcpp20/simulation.hpp | 12 +++++
 tests/tests.cpp                            | 54 ++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/include/fschuetz04/simcpp20/simulation.hpp b/include/fschuetz04/simcpp20/simulation.hpp
index ee98947..a745241 100644
--- a/include/fschuetz04/simcpp20/simulation.hpp
+++ b/include/fschuetz04/simcpp20/simulation.hpp
@@ -63,6 +63,18 @@ template <typename Time = double> class simulation {
     schedule(ev, delay);
     return ev;
   }
+  
+  /**
+   * Posts a callback to be executed as soon as possible.
+   * @param callback Callback to invoke, which has the following signature: `void callback()`.
+   * @return New pending event.
+   */
+  event_type post(std::function<void()> callback) {
+    auto ev = event();
+    ev.add_callback(callback);
+    schedule(ev);
+    return ev;
+  }
 
   /**
    * @tparam Value Value type of the event.
diff --git a/tests/tests.cpp b/tests/tests.cpp
index 68e33c7..cc5d672 100644
--- a/tests/tests.cpp
+++ b/tests/tests.cpp
@@ -167,3 +167,57 @@ TEST_CASE("all_of") {
     REQUIRE(finished);
   }
 }
+
+TEST_CASE("post event to simulation") {
+  simcpp20::simulation<> sim;
+
+  bool ran = false;
+  auto ev1 = sim.post([&ran]() { ran = true; });
+
+  sim.step();
+  REQUIRE(ran);
+  REQUIRE(ev1.processed());
+}
+
+TEST_CASE("post event ordering") {
+  simcpp20::simulation<> sim;
+
+  SECTION("between other pending events")
+  {
+    bool ran = false;
+
+    auto ev1 = sim.timeout(1);
+    auto ev2 = sim.post([&ran]() { ran = true; });
+
+    sim.step();
+    REQUIRE(ran);
+    REQUIRE(ev1.pending());
+    REQUIRE(ev2.processed());
+  }
+
+  SECTION("between multiple posted events")
+  {
+    bool ran1 = false;
+    bool ran2 = false;
+    bool ran3 = false;
+
+    auto ev1 = sim.post([&ran1]() { ran1 = true; });
+    auto ev2 = sim.post([&ran2]() { ran2 = true; });
+    auto ev3 = sim.post([&ran3]() { ran3 = true; });
+
+    sim.step();
+    REQUIRE(ran1);
+    REQUIRE_FALSE(ran2);
+    REQUIRE_FALSE(ran3);
+    
+    sim.step();
+    REQUIRE(ran1);
+    REQUIRE(ran2);
+    REQUIRE_FALSE(ran3);
+    
+    sim.step();
+    REQUIRE(ran1);
+    REQUIRE(ran2);
+    REQUIRE(ran3);
+  }
+}
\ No newline at end of file

From ab9a0a9f8967af8526e46dfd5fce8661171dbea2 Mon Sep 17 00:00:00 2001
From: Marco Satti <msatti@metrol.co.uk>
Date: Thu, 19 Mar 2026 11:50:42 +0000
Subject: [PATCH 2/3] Modify post function to accept delay parameter

---
 include/fschuetz04/simcpp20/simulation.hpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/fschuetz04/simcpp20/simulation.hpp b/include/fschuetz04/simcpp20/simulation.hpp
index a745241..fbf39c5 100644
--- a/include/fschuetz04/simcpp20/simulation.hpp
+++ b/include/fschuetz04/simcpp20/simulation.hpp
@@ -65,14 +65,15 @@ template <typename Time = double> class simulation {
   }
   
   /**
-   * Posts a callback to be executed as soon as possible.
+   * Posts a callback to be executed after the delay.
    * @param callback Callback to invoke, which has the following signature: `void callback()`.
+   * @param delay Delay before executing the callback. If default constructed, execute as soon as possible.
    * @return New pending event.
    */
-  event_type post(std::function<void()> callback) {
+  event_type post(std::function<void()> callback, Time delay = Time{0}) {
     auto ev = event();
     ev.add_callback(callback);
-    schedule(ev);
+    schedule(ev, delay);
     return ev;
   }
 

From 3523e07e770129cd9ae154eaf1cfafafb88ad3ce Mon Sep 17 00:00:00 2001
From: Marco Satti <msatti@metrol.co.uk>
Date: Thu, 19 Mar 2026 11:52:34 +0000
Subject: [PATCH 3/3] Add test in for post with delay

---
 tests/tests.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tests/tests.cpp b/tests/tests.cpp
index cc5d672..ce34e49 100644
--- a/tests/tests.cpp
+++ b/tests/tests.cpp
@@ -220,4 +220,22 @@ TEST_CASE("post event ordering") {
     REQUIRE(ran2);
     REQUIRE(ran3);
   }
+}
+
+TEST_CASE("post event with delay to simulation") {
+  simcpp20::simulation<> sim;
+
+  bool ran1 = false;
+  bool ran2 = false;
+
+  auto ev1 = sim.post([&ran1]() { ran1 = true; }, 2.0);
+  auto ev2 = sim.post([&ran2]() { ran2 = true; }, 1.0);
+
+  sim.step();
+  REQUIRE_FALSE(ran1);
+  REQUIRE(ran2);
+  
+  sim.step();
+  REQUIRE(ran1);
+  REQUIRE(ran2);
 }
\ No newline at end of file