From 47f2ad55096cd4c23d69acea482ceff9ed8431fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gu=C3=B0mundur=20F=2E=20A=C3=B0alsteinsson?=
 <gudmundur.adalsteinsson@marel.com>
Date: Fri, 16 Sep 2022 20:25:28 +0000
Subject: [PATCH] Refactor object::erase

---
 include/boost/json/impl/object.ipp | 85 ++++++++++++++++--------------
 include/boost/json/object.hpp      | 12 ++++-
 2 files changed, 56 insertions(+), 41 deletions(-)

diff --git a/include/boost/json/impl/object.ipp b/include/boost/json/impl/object.ipp
index 6c89762a2..1e395c0e3 100644
--- a/include/boost/json/impl/object.ipp
+++ b/include/boost/json/impl/object.ipp
@@ -508,30 +508,17 @@ object::
 erase(const_iterator pos) noexcept ->
     iterator
 {
-    auto p = begin() + (pos - begin());
-    if(t_->is_small())
-    {
-        p->~value_type();
-        --t_->size;
-        auto const pb = end();
-        if(p != end())
-        {
+    return do_erase(pos,
+        [this](iterator p) {
             // the casts silence warnings
             std::memcpy(
                 static_cast<void*>(p),
-                static_cast<void const*>(pb),
+                static_cast<void const*>(end()),
                 sizeof(*p));
-        }
-        return p;
-    }
-    remove(t_->bucket(p->key()), *p);
-    p->~value_type();
-    --t_->size;
-    if(p != end())
-    {
-        reindex_relocate(end(), p);
-    }
-    return p;
+        },
+        [this](iterator p) {
+            reindex_relocate(end(), p);
+        });
 }
 
 auto
@@ -551,30 +538,20 @@ object::
 stable_erase(const_iterator pos) noexcept ->
     iterator
 {
-    auto p = begin() + (pos - begin());
-    if(t_->is_small())
-    {
-        p->~value_type();
-        --t_->size;
-        if(p != end())
-        {
+    return do_erase(pos,
+        [this](iterator p) {
             // the casts silence warnings
             std::memmove(
                 static_cast<void*>(p),
                 static_cast<void const*>(p + 1),
                 sizeof(*p) * (end() - p));
-        }
-        return p;
-    }
-    remove(t_->bucket(p->key()), *p);
-    p->~value_type();
-    --t_->size;
-    auto pret = p;
-    for (; p != end(); ++p)
-    {
-        reindex_relocate(p + 1, p);
-    }
-    return pret;
+        },
+        [this](iterator p) {
+            for (; p != end(); ++p)
+            {
+                reindex_relocate(p + 1, p);
+            }
+        });
 }
 
 auto
@@ -863,6 +840,36 @@ destroy(
         (--last)->~key_value_pair();
 }
 
+template<class FS, class FB>
+auto
+object::
+do_erase(
+    const_iterator pos,
+    FS small_reloc,
+    FB big_reloc) noexcept
+    -> iterator
+{
+    auto p = begin() + (pos - begin());
+    if(t_->is_small())
+    {
+        p->~value_type();
+        --t_->size;
+        if(p != end())
+        {
+            small_reloc(p);
+        }
+        return p;
+    }
+    remove(t_->bucket(p->key()), *p);
+    p->~value_type();
+    --t_->size;
+    if(p != end())
+    {
+        big_reloc(p);
+    }
+    return p;
+}
+
 void
 object::
 reindex_relocate(
diff --git a/include/boost/json/object.hpp b/include/boost/json/object.hpp
index 378f2d9a5..2922079c2 100644
--- a/include/boost/json/object.hpp
+++ b/include/boost/json/object.hpp
@@ -1176,7 +1176,7 @@ class object
         References and iterators from `pos` to `end()`, both
         included, are invalidated. Other iterators and references
         are not invalidated.
-        The relative order of non-erased elements is preserved.
+        The relative order of remaining elements is preserved.
 
         @note
 
@@ -1202,7 +1202,7 @@ class object
 
         Remove the element which matches `key`, if it exists.
         All references and iterators are invalidated.
-        The relative order of non-erased elements is preserved.
+        The relative order of remaining elements is preserved.
 
         @par Complexity
         Linear in @ref size().
@@ -1621,6 +1621,14 @@ class object
         key_value_pair* first,
         key_value_pair* last) noexcept;
 
+    template<class FS, class FB>
+    auto
+    do_erase(
+        const_iterator pos,
+        FS small_reloc,
+        FB big_reloc) noexcept
+        -> iterator;
+
     inline
     void
     reindex_relocate(