From 7da4a34dc1d101310ccfab3acfb76388847f9fc3 Mon Sep 17 00:00:00 2001
From: Vadim Markovtsev <gmarkhor@gmail.com>
Date: Mon, 28 Nov 2022 11:55:58 +0100
Subject: [PATCH] Make "destroy" a compile-time constant + fix const allocator
 comparisons

---
 include/mimalloc.h | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/include/mimalloc.h b/include/mimalloc.h
index d70d28ed..81d387c3 100644
--- a/include/mimalloc.h
+++ b/include/mimalloc.h
@@ -471,7 +471,7 @@ template<class T1,class T2> bool operator!=(const mi_stl_allocator<T1>& , const
 #include <memory>      // std::shared_ptr
 
 // Common base class for STL allocators in a specific heap
-template<class T> struct _mi_heap_stl_allocator_common : public _mi_stl_allocator_common<T> {
+template<class T, bool destroy> struct _mi_heap_stl_allocator_common : public _mi_stl_allocator_common<T> {
   using typename _mi_stl_allocator_common<T>::size_type;
   using typename _mi_stl_allocator_common<T>::value_type;
   using typename _mi_stl_allocator_common<T>::pointer;
@@ -490,18 +490,18 @@ template<class T> struct _mi_heap_stl_allocator_common : public _mi_stl_allocato
   #endif
 
   void collect(bool force) { mi_heap_collect(this->heap.get(), force); }
-  template<class U> bool is_equal(const _mi_heap_stl_allocator_common<U>& x) { return (this->heap == x.heap); }
+  template<class U> bool is_equal(const _mi_heap_stl_allocator_common<U, destroy>& x) const { return (this->heap == x.heap); }
 
 protected:
   std::shared_ptr<mi_heap_t> heap;
-  template<class U> friend struct _mi_heap_stl_allocator_common;
+  template<class U, bool D> friend struct _mi_heap_stl_allocator_common;
   
-  _mi_heap_stl_allocator_common(bool destroy) {
+  _mi_heap_stl_allocator_common() {
     mi_heap_t* hp = mi_heap_new();
     this->heap.reset(hp, (destroy ? &heap_destroy : &heap_delete));  /* calls heap_delete/destroy when the refcount drops to zero */
   }
   _mi_heap_stl_allocator_common(const _mi_heap_stl_allocator_common& x) mi_attr_noexcept : heap(x.heap) { }
-  template<class U> _mi_heap_stl_allocator_common(const _mi_heap_stl_allocator_common<U>& x) mi_attr_noexcept : heap(x.heap) { }
+  template<class U> _mi_heap_stl_allocator_common(const _mi_heap_stl_allocator_common<U, destroy>& x) mi_attr_noexcept : heap(x.heap) { }
 
 private:
   static void heap_delete(mi_heap_t* hp)  { if (hp != NULL) { mi_heap_delete(hp); } }
@@ -509,11 +509,10 @@ private:
 };
 
 // STL allocator allocation in a specific heap
-template<class T> struct mi_heap_stl_allocator : public _mi_heap_stl_allocator_common<T> {
-  using typename _mi_heap_stl_allocator_common<T>::size_type;
-  mi_heap_stl_allocator() : _mi_heap_stl_allocator_common<T>(false) { }            /* delete on destruction */
-  mi_heap_stl_allocator(mi_heap_t* hp) : _mi_heap_stl_allocator_common<T>(hp) { }  /* no delete or destroy on the passed in heap */
-  template<class U> mi_heap_stl_allocator(const mi_heap_stl_allocator<U>& x) mi_attr_noexcept : _mi_heap_stl_allocator_common<T>(x) { }
+template<class T> struct mi_heap_stl_allocator : public _mi_heap_stl_allocator_common<T, false> {
+  using typename _mi_heap_stl_allocator_common<T, false>::size_type;
+  mi_heap_stl_allocator(mi_heap_t* hp) : _mi_heap_stl_allocator_common<T, false>(hp) { }  /* no delete or destroy on the passed in heap */
+  template<class U> mi_heap_stl_allocator(const mi_heap_stl_allocator<U>& x) mi_attr_noexcept : _mi_heap_stl_allocator_common<T, false>(x) { }
 
   mi_heap_stl_allocator select_on_container_copy_construction() const { return *this; }
   void deallocate(T* p, size_type) { mi_free(p); }
@@ -526,10 +525,9 @@ template<class T1, class T2> bool operator!=(const mi_heap_stl_allocator<T1>& x,
 
 // STL allocator allocation in a specific heap, where `free` does nothing and 
 // the heap is destroyed in one go on destruction -- use with care!
-template<class T> struct mi_heap_destroy_stl_allocator : public _mi_heap_stl_allocator_common<T> {
-  using typename _mi_heap_stl_allocator_common<T>::size_type;
-  mi_heap_destroy_stl_allocator() : _mi_heap_stl_allocator_common<T>(true) { }   /* destroy on destruction */
-  template<class U> mi_heap_destroy_stl_allocator(const mi_heap_destroy_stl_allocator<U>& x) mi_attr_noexcept : _mi_heap_stl_allocator_common<T>(x) { }
+template<class T> struct mi_heap_destroy_stl_allocator : public _mi_heap_stl_allocator_common<T, true> {
+  using typename _mi_heap_stl_allocator_common<T, true>::size_type;
+  template<class U> mi_heap_destroy_stl_allocator(const mi_heap_destroy_stl_allocator<U>& x) mi_attr_noexcept : _mi_heap_stl_allocator_common<T, true>(x) { }
 
   mi_heap_destroy_stl_allocator select_on_container_copy_construction() const { return *this; }
   void deallocate(T* p, size_type) { /* do nothing as we destroy the heap on destruct. */ }