From 6911e6adce3e1d714889b8c144569e3a2ebb23a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ion=20Gazta=C3=B1aga?= <igaztanaga@gmail.com>
Date: Fri, 31 Oct 2025 15:37:07 +0100
Subject: [PATCH] Implement erase/erase_if for list and slist

---
 .../container/detail/compare_functors.hpp     |  7 +++--
 include/boost/container/list.hpp              | 22 ++++++++++++++++
 include/boost/container/slist.hpp             | 22 ++++++++++++++++
 test/list_test.hpp                            | 26 +++++++++++++++++++
 4 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/include/boost/container/detail/compare_functors.hpp b/include/boost/container/detail/compare_functors.hpp
index 9a35274..e15320b 100644
--- a/include/boost/container/detail/compare_functors.hpp
+++ b/include/boost/container/detail/compare_functors.hpp
@@ -36,8 +36,11 @@ class equal_to_value
       :  t_(t)
    {}
 
-   inline bool operator()(const value_type &t)const
-   {  return t_ == t;   }
+   template <class U>
+   inline bool operator()(const U &t)const
+   {
+      return t_ == t;
+   }
 };
 
 template<class Node, class Pred, class Ret = bool>
diff --git a/include/boost/container/list.hpp b/include/boost/container/list.hpp
index 1346537..1d70898 100644
--- a/include/boost/container/list.hpp
+++ b/include/boost/container/list.hpp
@@ -1487,6 +1487,28 @@ class list
 
 };
 
+//! <b>Effects</b>: Erases all elements that compare equal to v from the container c.
+//!
+//! <b>Complexity</b>: Linear.
+template <class T, class A, class U>
+inline typename list<T, A>::size_type erase(list<T, A>& c, const U& v)
+{
+  typename list<T, A>::size_type old_size = c.size();
+  c.remove_if(equal_to_value<U>(v));
+  return old_size - c.size();
+}
+
+//! <b>Effects</b>: Erases all elements that satisfy the predicate pred from the container c.
+//!
+//! <b>Complexity</b>: Linear.
+template <class T, class A, class Pred>
+inline typename list<T, A>::size_type erase_if(list<T, A>& c, Pred pred)
+{
+  typename list<T, A>::size_type old_size = c.size();
+  c.remove_if(pred);
+  return old_size - c.size();
+}
+
 #ifndef BOOST_CONTAINER_NO_CXX17_CTAD
 template <typename InputIterator>
 list(InputIterator, InputIterator) ->
diff --git a/include/boost/container/slist.hpp b/include/boost/container/slist.hpp
index 849f929..d6ecf61 100644
--- a/include/boost/container/slist.hpp
+++ b/include/boost/container/slist.hpp
@@ -1658,6 +1658,28 @@ class slist
    #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 };
 
+//! <b>Effects</b>: Erases all elements that compare equal to v from the container c.
+//!
+//! <b>Complexity</b>: Linear.
+template <class T, class A, class U>
+inline typename slist<T, A>::size_type erase(slist<T, A>& c, const U& v)
+{
+  typename slist<T, A>::size_type old_size = c.size();
+  c.remove_if(equal_to_value<U>(v));
+  return old_size - c.size();
+}
+
+//! <b>Effects</b>: Erases all elements that satisfy the predicate pred from the container c.
+//!
+//! <b>Complexity</b>: Linear.
+template <class T, class A, class Pred>
+inline typename slist<T, A>::size_type erase_if(slist<T, A>& c, Pred pred)
+{
+  typename slist<T, A>::size_type old_size = c.size();
+  c.remove_if(pred);
+  return old_size - c.size();
+}
+
 #ifndef BOOST_CONTAINER_NO_CXX17_CTAD
 
 template <typename InpIt>
diff --git a/test/list_test.hpp b/test/list_test.hpp
index 404c5b1..7b53dbc 100644
--- a/test/list_test.hpp
+++ b/test/list_test.hpp
@@ -83,6 +83,32 @@ bool list_copyable_only(V1 &boostlist, V2 &stdlist, boost::container::dtl::true_
       boostlist.assign(v1.begin(), v1.end());
       stdlist.assign(v2.begin(), v2.end());
       if(!test::CheckEqualContainers(boostlist, stdlist)) return 1;
+
+      //test erase/erase_if
+      IntType aux_vect[50];
+      for(int i = 0; i < 50; ++i){
+         aux_vect[i] = i;
+      }
+      int aux_vect2[50];
+      for(int i = 0; i < 50; ++i){
+         aux_vect2[i] = i;
+      }
+
+      boostlist.clear();
+      stdlist.clear();
+      boostlist.insert(boostlist.end()
+                     ,boost::make_move_iterator(&aux_vect[0])
+                     ,boost::make_move_iterator(aux_vect + 50));
+      stdlist.insert(stdlist.end(), aux_vect2, aux_vect2 + 50);
+      if(!test::CheckEqualContainers(boostlist, stdlist)) return false;
+
+      if (1 != erase(boostlist, 25))
+         return 1;
+      stdlist.erase(boost::container::find(stdlist.begin(), stdlist.end(), 25));
+      if(!test::CheckEqualContainers(boostlist, stdlist)) return false;
+
+      if (0 != erase(boostlist, 25))
+         return 1;
    }
    {  //List(const List &, alloc)
       ::boost::movelib::unique_ptr<V1> const pv1 = ::boost::movelib::make_unique<V1>(boostlist, typename V1::allocator_type());