From 44a0d7c3c521875756d187e17d25d8294f84be1b Mon Sep 17 00:00:00 2001
From: John Wellbelove <john.wellbelove@asterconsulting.co.uk>
Date: Thu, 27 Feb 2025 10:02:56 +0000
Subject: [PATCH] Added etl::create_linked_list and etl::detach_linked_list to
 the intrusive link utilities

---
 include/etl/intrusive_links.h | 196 ++++++++++++++++++++
 test/test_intrusive_links.cpp | 337 ++++++++++++++++++++++++++++++++++
 2 files changed, 533 insertions(+)

diff --git a/include/etl/intrusive_links.h b/include/etl/intrusive_links.h
index 577f5010..1ca2479e 100644
--- a/include/etl/intrusive_links.h
+++ b/include/etl/intrusive_links.h
@@ -404,6 +404,112 @@ namespace etl
     }
   }
 
+#if ETL_USING_CPP17
+  //***************************************************************************
+  /// Create a linked list from a number of forward_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink& first, TLinks&... links)
+  {
+    TLink* current = &first;
+    ((current->etl_next = &links, current = &links), ...);
+
+    return current;
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of forward_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink* first, TLinks*... links)
+  {
+    if (first != ETL_NULLPTR)
+    {
+      return create_linked_list(*first, (*links)...);
+    }
+    else
+    {
+      return nullptr;
+    }
+  }
+#elif ETL_USING_CPP11
+  //***************************************************************************
+  /// Create a linked list from a number of forward_link nodes.
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink& first)
+  {
+    return &first;
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of forward_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink& first, TLink& next, TLinks&... links)
+  {
+    first.etl_next = &next;
+    return create_linked_list(next, static_cast<TLink&>(links)...);
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of forward_link nodes.
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink* first)
+  {
+    if (first != ETL_NULLPTR)
+    {
+      return create_linked_list(*first);
+    }
+    else
+    {
+      return ETL_NULLPTR;
+    }
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of forward_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink* first, TLink* next, TLinks*... links)
+  {
+    if (first != ETL_NULLPTR)
+    {
+      return create_linked_list(*first, *next, static_cast<TLink&>(*links)...);
+    }
+    else
+    {
+      return ETL_NULLPTR;
+    }
+  }
+#endif
+
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, void>::type
+    detach_linked_list(TLink& first)
+  {
+    link_clear_range(first);
+  }
+
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_forward_link<TLink>::value, void>::type
+    detach_linked_list(TLink* first)
+  {
+    if (first != ETL_NULLPTR)
+    {
+      detach_linked_list(*first);
+    }
+  }
+
   //***************************************************************************
   /// A bidirectional link.
   //***************************************************************************
@@ -829,6 +935,96 @@ namespace etl
     etl::link_clear_range(*start);
   }
 
+#if ETL_USING_CPP17
+  //***************************************************************************
+  /// Create a linked list from a number of bidirectional_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink& first, TLinks&... links)
+  {
+    TLink* current = &first;
+    ((current->etl_next = &links, static_cast<TLink&>(links).etl_previous = current, current = &links), ...);
+    current->etl_next = ETL_NULLPTR;
+
+    return current;
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of bidirectional_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink* first, TLinks*... links)
+  {
+    TLink* current = first;
+    ((current->etl_next = links, static_cast<TLink*>(links)->etl_previous = current, current = links), ...);
+    current->etl_next = ETL_NULLPTR;
+
+    return current;
+  }
+#elif ETL_USING_CPP11
+
+  //***************************************************************************
+  /// Create a linked list from a number of bidirectional_link nodes.
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink& first)
+  {
+    return &first;
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of bidirectional_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink& first, TLink& next, TLinks&... links)
+  {
+    first.etl_next    = &next;
+    next.etl_previous = &first;
+
+    return create_linked_list(next, static_cast<TLink&>(links)...);
+  }
+
+  //***************************************************************************
+  /// Create a linked list from a number of bidirectional_link nodes.
+  //***************************************************************************
+  template <typename TLink, typename... TLinks>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, TLink*>::type
+    create_linked_list(TLink* first, TLink* next, TLinks*... links)
+  {
+    if (first != ETL_NULLPTR)
+    {
+      return create_linked_list(*first, *next, static_cast<TLink&>(*links)...);
+    }
+    else
+    {
+      return ETL_NULLPTR;
+    }
+  }
+#endif
+
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, void>::type
+    detach_linked_list(TLink& first)
+  {
+    link_clear_range(first);
+  }
+
+  //***************************************************************************
+  template <typename TLink>
+  typename etl::enable_if<etl::is_bidirectional_link<TLink>::value, void>::type
+    detach_linked_list(TLink* first)
+  {
+    if (first != ETL_NULLPTR)
+    {
+      detach_linked_list(*first);
+    }
+  }
+
   //***************************************************************************
   /// A binary tree link.
   //***************************************************************************
diff --git a/test/test_intrusive_links.cpp b/test/test_intrusive_links.cpp
index 13a09c5b..cdfa1d8c 100644
--- a/test/test_intrusive_links.cpp
+++ b/test/test_intrusive_links.cpp
@@ -32,6 +32,8 @@ SOFTWARE.
 
 #include "etl/intrusive_links.h"
 
+#include <vector>
+
 namespace
 {
   //*******************************************************
@@ -157,6 +159,166 @@ namespace
       CHECK_EQUAL(0, pdata->value);
     }
 
+    //*************************************************************************
+    TEST(test_create_linked_list_multiple_forward_links_as_references)
+    {
+      FData data0(0);
+      FData data1(1);
+      FData data2(2);
+      FData data3(3);
+
+      FLink0* last0 = etl::create_linked_list<FLink0>(data0, data1, data2, data3);
+      CHECK(last0 == &data3);
+      CHECK(data0.FLink0::etl_next == &data1);
+      CHECK(data1.FLink0::etl_next == &data2);
+      CHECK(data2.FLink0::etl_next == &data3);
+      CHECK(data3.FLink0::etl_next == ETL_NULLPTR);
+
+      FLink1* last1 = etl::create_linked_list<FLink1>(data3, data2, data1, data0);
+      CHECK(last1 == &data0);
+      CHECK(data3.FLink1::etl_next == &data2);
+      CHECK(data2.FLink1::etl_next == &data1);
+      CHECK(data1.FLink1::etl_next == &data0);
+      CHECK(data0.FLink1::etl_next == ETL_NULLPTR);
+
+      FData* pdata;
+
+      pdata = static_cast<FData*>(data0.FLink0::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink0::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink0::etl_next);
+      CHECK_EQUAL(3, pdata->value);
+
+      pdata = static_cast<FData*>(data3.FLink1::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink1::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink1::etl_next);
+      CHECK_EQUAL(0, pdata->value);
+
+      FData data4(4);
+      FData data5(5);
+      FData data6(6);
+      FData data7(7);
+
+      auto last2 = etl::create_linked_list<FLink0>(*last0, data4, data5, data6, data7);
+      CHECK(last2 == &data7);
+      CHECK(data0.FLink0::etl_next == &data1);
+      CHECK(data1.FLink0::etl_next == &data2);
+      CHECK(data2.FLink0::etl_next == &data3);
+      CHECK(data3.FLink0::etl_next == &data4);
+      CHECK(data4.FLink0::etl_next == &data5);
+      CHECK(data5.FLink0::etl_next == &data6);
+      CHECK(data6.FLink0::etl_next == &data7);
+      CHECK(data7.FLink0::etl_next == ETL_NULLPTR);
+    }
+
+    //*************************************************************************
+    TEST(test_create_linked_list_multiple_forward_links_as_pointers)
+    {
+      FData data0(0);
+      FData data1(1);
+      FData data2(2);
+      FData data3(3);
+
+      FLink0* last0 = etl::create_linked_list<FLink0>(&data0, &data1, &data2, &data3);
+      CHECK(last0 == &data3);
+      CHECK(data0.FLink0::etl_next == &data1);
+      CHECK(data1.FLink0::etl_next == &data2);
+      CHECK(data2.FLink0::etl_next == &data3);
+      CHECK(data3.FLink0::etl_next == ETL_NULLPTR);
+
+      FLink1* last1 = etl::create_linked_list<FLink1>(&data3, &data2, &data1, &data0);
+      CHECK(last1 == &data0);
+      CHECK(data3.FLink1::etl_next == &data2);
+      CHECK(data2.FLink1::etl_next == &data1);
+      CHECK(data1.FLink1::etl_next == &data0);
+      CHECK(data0.FLink1::etl_next == ETL_NULLPTR);
+
+      FData* pdata;
+
+      pdata = static_cast<FData*>(data0.FLink0::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink0::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink0::etl_next);
+      CHECK_EQUAL(3, pdata->value);
+
+      pdata = static_cast<FData*>(data3.FLink1::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink1::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<FData*>(pdata->FLink1::etl_next);
+      CHECK_EQUAL(0, pdata->value);
+
+      FData data4(4);
+      FData data5(5);
+      FData data6(6);
+      FData data7(7);
+
+      auto last2 = etl::create_linked_list<FLink0>(last0, &data4, &data5, &data6, &data7);
+      CHECK(last2 == &data7);
+      CHECK(data0.FLink0::etl_next == &data1);
+      CHECK(data1.FLink0::etl_next == &data2);
+      CHECK(data2.FLink0::etl_next == &data3);
+      CHECK(data3.FLink0::etl_next == &data4);
+      CHECK(data4.FLink0::etl_next == &data5);
+      CHECK(data5.FLink0::etl_next == &data6);
+      CHECK(data6.FLink0::etl_next == &data7);
+      CHECK(data7.FLink0::etl_next == ETL_NULLPTR);
+    }
+
+    //*************************************************************************
+    TEST(test_detach_linked_list_multiple_forward_links_as_references)
+    {
+      FData data0(0);
+      FData data1(1);
+      FData data2(2);
+      FData data3(3);
+
+      etl::create_linked_list<FLink0>(data0, data1, data2, data3);
+      etl::create_linked_list<FLink1>(data3, data2, data1, data0);
+
+      etl::detach_linked_list<FLink0>(data0);
+      etl::detach_linked_list<FLink1>(data3);
+
+      CHECK(data0.FLink0::etl_next == ETL_NULLPTR);
+      CHECK(data1.FLink0::etl_next == ETL_NULLPTR);
+      CHECK(data2.FLink0::etl_next == ETL_NULLPTR);
+      CHECK(data3.FLink0::etl_next == ETL_NULLPTR);
+
+      CHECK(data0.FLink1::etl_next == ETL_NULLPTR);
+      CHECK(data1.FLink1::etl_next == ETL_NULLPTR);
+      CHECK(data2.FLink1::etl_next == ETL_NULLPTR);
+      CHECK(data3.FLink1::etl_next == ETL_NULLPTR);
+    }
+
+    //*************************************************************************
+    TEST(test_detach_linked_list_multiple_forward_links_as_pointers)
+    {
+      FData data0(0);
+      FData data1(1);
+      FData data2(2);
+      FData data3(3);
+
+      etl::create_linked_list<FLink0>(data0, data1, data2, data3);
+      etl::create_linked_list<FLink1>(data3, data2, data1, data0);
+
+      etl::detach_linked_list<FLink0>(&data0);
+      etl::detach_linked_list<FLink1>(&data3);
+
+      CHECK(data0.FLink0::etl_next == ETL_NULLPTR);
+      CHECK(data1.FLink0::etl_next == ETL_NULLPTR);
+      CHECK(data2.FLink0::etl_next == ETL_NULLPTR);
+      CHECK(data3.FLink0::etl_next == ETL_NULLPTR);
+
+      CHECK(data0.FLink1::etl_next == ETL_NULLPTR);
+      CHECK(data1.FLink1::etl_next == ETL_NULLPTR);
+      CHECK(data2.FLink1::etl_next == ETL_NULLPTR);
+      CHECK(data3.FLink1::etl_next == ETL_NULLPTR);
+    }
+
     //*************************************************************************
     TEST(test_link_forward_link_get_set)
     {
@@ -537,6 +699,181 @@ namespace
       data2.BLink0::unlink();
     }
 
+    //*************************************************************************
+    TEST(test_create_linked_list_multiple_bidirectional_links_as_references)
+    {
+      BData data0(0);
+      BData data1(1);
+      BData data2(2);
+      BData data3(3);
+
+      BLink0* last0 = etl::create_linked_list<BLink0>(data0, data1, data2, data3);
+      CHECK(last0 == &data3);
+      CHECK(data0.BLink0::etl_previous == ETL_NULLPTR);
+      CHECK(data0.BLink0::etl_next     == &data1);
+      CHECK(data1.BLink0::etl_previous == &data0);
+      CHECK(data1.BLink0::etl_next     == &data2);
+      CHECK(data2.BLink0::etl_previous == &data1);
+      CHECK(data2.BLink0::etl_next     == &data3);
+      CHECK(data3.BLink0::etl_previous == &data2);
+      CHECK(data3.BLink0::etl_next     == ETL_NULLPTR);
+
+      BLink1* last1 = etl::create_linked_list<BLink1>(data3, data2, data1, data0);
+      CHECK(last1 == &data0);
+      CHECK(data3.BLink1::etl_previous == ETL_NULLPTR);
+      CHECK(data3.BLink1::etl_next     == &data2);
+      CHECK(data2.BLink1::etl_previous == &data3);
+      CHECK(data2.BLink1::etl_next     == &data1);
+      CHECK(data1.BLink1::etl_previous == &data2);
+      CHECK(data1.BLink1::etl_next     == &data0);
+      CHECK(data0.BLink1::etl_previous == &data1);
+      CHECK(data0.BLink1::etl_next     == ETL_NULLPTR);
+
+      BData* pdata;
+
+      pdata = static_cast<BData*>(data0.BLink0::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink0::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink0::etl_next);
+      CHECK_EQUAL(3, pdata->value);
+
+      pdata = static_cast<BData*>(data3.BLink1::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink1::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink1::etl_next);
+      CHECK_EQUAL(0, pdata->value);
+
+      BData data4(4);
+      BData data5(5);
+      BData data6(6);
+      BData data7(7);
+
+      auto last2 = etl::create_linked_list<BLink0>(*last0, data4, data5, data6, data7);
+      CHECK(last2 == &data7);
+      CHECK(data0.BLink0::etl_previous == ETL_NULLPTR);
+      CHECK(data0.BLink0::etl_next     == &data1);
+      CHECK(data1.BLink0::etl_previous == &data0);
+      CHECK(data1.BLink0::etl_next     == &data2);
+      CHECK(data2.BLink0::etl_previous == &data1);
+      CHECK(data2.BLink0::etl_next     == &data3);
+      CHECK(data3.BLink0::etl_previous == &data2);
+      CHECK(data3.BLink0::etl_next     == &data4);
+      CHECK(data4.BLink0::etl_previous == &data3);
+      CHECK(data4.BLink0::etl_next     == &data5);
+      CHECK(data5.BLink0::etl_previous == &data4);
+      CHECK(data5.BLink0::etl_next     == &data6);
+      CHECK(data6.BLink0::etl_previous == &data5);
+      CHECK(data6.BLink0::etl_next     == &data7);
+      CHECK(data7.BLink0::etl_next     == ETL_NULLPTR);
+    }
+
+    //*************************************************************************
+    TEST(test_create_linked_list_multiple_bidirectional_links_as_pointers)
+    {
+      BData data0(0);
+      BData data1(1);
+      BData data2(2);
+      BData data3(3);
+
+      BLink0* last0 = etl::create_linked_list<BLink0>(&data0, &data1, &data2, &data3);
+      CHECK(last0 == &data3);
+      CHECK(data0.BLink0::etl_next == &data1);
+      CHECK(data1.BLink0::etl_next == &data2);
+      CHECK(data2.BLink0::etl_next == &data3);
+      CHECK(data3.BLink0::etl_next == ETL_NULLPTR);
+
+      BLink1* last1 = etl::create_linked_list<BLink1>(&data3, &data2, &data1, &data0);
+      CHECK(last1 == &data0);
+      CHECK(data3.BLink1::etl_next == &data2);
+      CHECK(data2.BLink1::etl_next == &data1);
+      CHECK(data1.BLink1::etl_next == &data0);
+      CHECK(data0.BLink1::etl_next == ETL_NULLPTR);
+
+      BData* pdata;
+
+      pdata = static_cast<BData*>(data0.BLink0::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink0::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink0::etl_next);
+      CHECK_EQUAL(3, pdata->value);
+
+      pdata = static_cast<BData*>(data3.BLink1::etl_next);
+      CHECK_EQUAL(2, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink1::etl_next);
+      CHECK_EQUAL(1, pdata->value);
+      pdata = static_cast<BData*>(pdata->BLink1::etl_next);
+      CHECK_EQUAL(0, pdata->value);
+
+      BData data4(4);
+      BData data5(5);
+      BData data6(6);
+      BData data7(7);
+
+      auto last2 = etl::create_linked_list<BLink0>(last0, &data4, &data5, &data6, &data7);
+      CHECK(last2 == &data7);
+      CHECK(data0.BLink0::etl_next == &data1);
+      CHECK(data1.BLink0::etl_next == &data2);
+      CHECK(data2.BLink0::etl_next == &data3);
+      CHECK(data3.BLink0::etl_next == &data4);
+      CHECK(data4.BLink0::etl_next == &data5);
+      CHECK(data5.BLink0::etl_next == &data6);
+      CHECK(data6.BLink0::etl_next == &data7);
+      CHECK(data7.BLink0::etl_next == ETL_NULLPTR);
+    }
+
+    //*************************************************************************
+    TEST(test_detach_linked_list_multiple_bidirectional_links_as_references)
+    {
+      BData data0(0);
+      BData data1(1);
+      BData data2(2);
+      BData data3(3);
+
+      etl::create_linked_list<BLink0>(data0, data1, data2, data3);
+      etl::create_linked_list<BLink1>(data3, data2, data1, data0);
+
+      etl::detach_linked_list<BLink0>(data0);
+      etl::detach_linked_list<BLink1>(data3);
+
+      CHECK(data0.BLink0::etl_next == ETL_NULLPTR);
+      CHECK(data1.BLink0::etl_next == ETL_NULLPTR);
+      CHECK(data2.BLink0::etl_next == ETL_NULLPTR);
+      CHECK(data3.BLink0::etl_next == ETL_NULLPTR);
+
+      CHECK(data0.BLink1::etl_next == ETL_NULLPTR);
+      CHECK(data1.BLink1::etl_next == ETL_NULLPTR);
+      CHECK(data2.BLink1::etl_next == ETL_NULLPTR);
+      CHECK(data3.BLink1::etl_next == ETL_NULLPTR);
+    }
+
+    //*************************************************************************
+    TEST(test_detach_linked_list_multiple_bidirectional_links_as_pointers)
+    {
+      BData data0(0);
+      BData data1(1);
+      BData data2(2);
+      BData data3(3);
+
+      etl::create_linked_list<BLink0>(data0, data1, data2, data3);
+      etl::create_linked_list<BLink1>(data3, data2, data1, data0);
+
+      etl::detach_linked_list<BLink0>(&data0);
+      etl::detach_linked_list<BLink1>(&data3);
+
+      CHECK(data0.BLink0::etl_next == ETL_NULLPTR);
+      CHECK(data1.BLink0::etl_next == ETL_NULLPTR);
+      CHECK(data2.BLink0::etl_next == ETL_NULLPTR);
+      CHECK(data3.BLink0::etl_next == ETL_NULLPTR);
+
+      CHECK(data0.BLink1::etl_next == ETL_NULLPTR);
+      CHECK(data1.BLink1::etl_next == ETL_NULLPTR);
+      CHECK(data2.BLink1::etl_next == ETL_NULLPTR);
+      CHECK(data3.BLink1::etl_next == ETL_NULLPTR);
+    }
+
     //*************************************************************************
     TEST(test_link_bidirectional_link_get_set)
     {