kstd: ring_buffer: implement pop_front()

2 files changed, 53 insertions, 0 deletions

diff --git a/libs/kstd/kstd/ring_buffer.hpp b/libs/kstd/kstd/ring_buffer.hpp
index af70e991..5039c7b4 100644
--- a/libs/kstd/kstd/ring_buffer.hpp
+++ b/libs/kstd/kstd/ring_buffer.hpp
@@ -534,6 +534,21 @@ namespace kstd
       return true;
     }
 
+    //! Remove the first element in the buffer.
+    //!
+    //! @warning This function will panic if the buffer is empty.
+    constexpr auto pop_front() -> void
+    {
+      if (empty())
+      {
+        os::panic("[KSTD] Tried to pop an element from an empty ring_buffer!");
+      }
+
+      std::destroy_at(element_at(0));
+      m_read_index = (m_read_index + 1) % capacity();
+      --m_size;
+    }
+
     //! @}
 
   private:
diff --git a/libs/kstd/kstd/ring_buffer.tests.cpp b/libs/kstd/kstd/ring_buffer.tests.cpp
index 0b332494..479283ed 100644
--- a/libs/kstd/kstd/ring_buffer.tests.cpp
+++ b/libs/kstd/kstd/ring_buffer.tests.cpp
@@ -1105,6 +1105,12 @@ SCENARIO("Ring Buffer modifiers", "[kstd][ring_buffer]")
     {
       REQUIRE(buffer.try_push_back(1));
     }
+
+    THEN("popping an element panics")
+    {
+      REQUIRE_THROWS_MATCHES(buffer.pop_front(), kstd::tests::os_panic,
+                             Catch::Matchers::Message("[KSTD] Tried to pop an element from an empty ring_buffer!"));
+    }
   }
 
   GIVEN("A ring buffer with a capacity of 5 containing 3 elements")
@@ -1242,6 +1248,38 @@ SCENARIO("Ring Buffer modifiers", "[kstd][ring_buffer]")
         }
       }
     }
+
+    WHEN("popping an element")
+    {
+      buffer.pop_front();
+
+      THEN("the size is 2")
+      {
+        REQUIRE(buffer.size() == 2);
+      }
+
+      THEN("the buffer is not empty")
+      {
+        REQUIRE_FALSE(buffer.empty());
+      }
+    }
+
+    WHEN("popping 3 elements")
+    {
+      buffer.pop_front();
+      buffer.pop_front();
+      buffer.pop_front();
+
+      THEN("the size is 0")
+      {
+        REQUIRE(buffer.size() == 0);
+      }
+
+      THEN("the buffer is empty")
+      {
+        REQUIRE(buffer.empty());
+      }
+    }
   }
 
   GIVEN("A full ring buffer of static operation trackers")