From 9cdef8e39943c0a3e645417ecb0c87d22d369675 Mon Sep 17 00:00:00 2001
From: John Wellbelove <github@wellbelove.co.uk>
Date: Thu, 12 Dec 2024 19:42:54 +0000
Subject: [PATCH] Added return reference from stack::emplace

---
 include/etl/stack.h | 24 ++++++++++++++++++------
 test/test_stack.cpp | 20 +++++++++++++++-----
 2 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/include/etl/stack.h b/include/etl/stack.h
index a292218a3..1c3759060 100644
--- a/include/etl/stack.h
+++ b/include/etl/stack.h
@@ -283,13 +283,15 @@ namespace etl
     ///\param value The value to push to the stack.
     //*************************************************************************
     template <typename ... Args>
-    void emplace(Args && ... args)
+    reference emplace(Args && ... args)
     {
 #if defined(ETL_CHECK_PUSH_POP)
       ETL_ASSERT(!full(), ETL_ERROR(stack_full));
 #endif
       base_t::add_in();
       ::new (&p_buffer[top_index]) T(etl::forward<Args>(args)...);
+
+      return p_buffer[top_index];
     }
 #else
     //*************************************************************************
@@ -297,13 +299,15 @@ namespace etl
     /// If asserts or exceptions are enabled, throws an etl::stack_full if the stack is already full.
     ///\param value The value to push to the stack.
     //*************************************************************************
-    void emplace()
+    reference emplace()
     {
 #if defined(ETL_CHECK_PUSH_POP)
       ETL_ASSERT(!full(), ETL_ERROR(stack_full));
 #endif
       base_t::add_in();
       ::new (&p_buffer[top_index]) T();
+
+      return p_buffer[top_index];
     }
 
     //*************************************************************************
@@ -312,13 +316,15 @@ namespace etl
     ///\param value The value to push to the stack.
     //*************************************************************************
     template <typename T1>
-    void emplace(const T1& value1)
+    reference emplace(const T1& value1)
     {
 #if defined(ETL_CHECK_PUSH_POP)
       ETL_ASSERT(!full(), ETL_ERROR(stack_full));
 #endif
       base_t::add_in();
       ::new (&p_buffer[top_index]) T(value1);
+
+      return p_buffer[top_index];
     }
 
     //*************************************************************************
@@ -327,13 +333,15 @@ namespace etl
     ///\param value The value to push to the stack.
     //*************************************************************************
     template <typename T1, typename T2>
-    void emplace(const T1& value1, const T2& value2)
+    reference emplace(const T1& value1, const T2& value2)
     {
 #if defined(ETL_CHECK_PUSH_POP)
       ETL_ASSERT(!full(), ETL_ERROR(stack_full));
 #endif
       base_t::add_in();
       ::new (&p_buffer[top_index]) T(value1, value2);
+
+      return p_buffer[top_index];
     }
 
     //*************************************************************************
@@ -342,13 +350,15 @@ namespace etl
     ///\param value The value to push to the stack.
     //*************************************************************************
     template <typename T1, typename T2, typename T3>
-    void emplace(const T1& value1, const T2& value2, const T3& value3)
+    reference emplace(const T1& value1, const T2& value2, const T3& value3)
     {
 #if defined(ETL_CHECK_PUSH_POP)
       ETL_ASSERT(!full(), ETL_ERROR(stack_full));
 #endif
       base_t::add_in();
       ::new (&p_buffer[top_index]) T(value1, value2, value3);
+
+      return p_buffer[top_index];
     }
 
     //*************************************************************************
@@ -357,13 +367,15 @@ namespace etl
     ///\param value The value to push to the stack.
     //*************************************************************************
     template <typename T1, typename T2, typename T3, typename T4>
-    void emplace(const T1& value1, const T2& value2, const T3& value3, const T4& value4)
+    reference emplace(const T1& value1, const T2& value2, const T3& value3, const T4& value4)
     {
 #if defined(ETL_CHECK_PUSH_POP)
       ETL_ASSERT(!full(), ETL_ERROR(stack_full));
 #endif
       base_t::add_in();
       ::new (&p_buffer[top_index]) T(value1, value2, value3, value4);
+
+      return p_buffer[top_index];
     }
 #endif
 
diff --git a/test/test_stack.cpp b/test/test_stack.cpp
index b27f7e115..81d35b467 100644
--- a/test/test_stack.cpp
+++ b/test/test_stack.cpp
@@ -231,28 +231,38 @@ namespace
     {
       etl::stack<Item, 5> stack;
 
-      stack.emplace();
+      Item& item1 = stack.emplace();
       CHECK_EQUAL(1U, stack.size());
 
-      stack.emplace('b', 2, 2.3);
+      Item& item2 = stack.emplace('b', 2, 2.3);
       CHECK_EQUAL(2U, stack.size());
 
-      stack.emplace('c', 3, 3.4);
+      Item& item3 = stack.emplace('c', 3, 3.4);
       CHECK_EQUAL(3U, stack.size());
 
-      stack.emplace('d', 4, 4.5);
+      Item& item4 = stack.emplace('d', 4, 4.5);
       CHECK_EQUAL(4U, stack.size());
 
-      stack.emplace('e', 5, 5.6);
+      Item& item5 = stack.emplace('e', 5, 5.6);
       CHECK_EQUAL(5U, stack.size());
 
+      CHECK(item1 == Item('a', 1, 1.2));
+      CHECK(item2 == Item('b', 2, 2.3));
+      CHECK(item3 == Item('c', 3, 3.4));
+      CHECK(item4 == Item('d', 4, 4.5));
+      CHECK(item5 == Item('e', 5, 5.6));
+
       CHECK(stack.top() == Item('e', 5, 5.6));
+      
       stack.pop();
       CHECK(stack.top() == Item('d', 4, 4.5));
+      
       stack.pop();
       CHECK(stack.top() == Item('c', 3, 3.4));
+      
       stack.pop();
       CHECK(stack.top() == Item('b', 2, 2.3));
+      
       stack.pop();
       CHECK(stack.top() == Item('a', 1, 1.2));
     }