test of unique_ptr with std::default_delete and a custom deleter

tests/run/cpp_smart_ptr.pyx

@@ -2,12 +2,16 @@
 # mode: run
 # tag: cpp, werror
 
-from libcpp.memory cimport unique_ptr, shared_ptr
+from libcpp.memory cimport unique_ptr, shared_ptr, default_delete 
+from libcpp cimport nullptr
 
 cdef extern from "cpp_smart_ptr_helper.h":
     cdef cppclass CountAllocDealloc:
         CountAllocDealloc(int*, int*)
 
+    cdef cppclass FreePtr[T]:
+        pass
+
 def test_unique_ptr():
     """
     >>> test_unique_ptr()
@@ -19,3 +23,21 @@ def test_unique_ptr():
     x_ptr.reset()
     assert alloc_count == 1
     assert dealloc_count == 1
+
+    ##Repeat the above test with an explicit default_delete type
+    alloc_count = 0
+    dealloc_count = 0
+    cdef unique_ptr[CountAllocDealloc,default_delete[CountAllocDealloc]] x_ptr2
+    x_ptr2.reset(new CountAllocDealloc(&alloc_count, &dealloc_count))
+    assert alloc_count == 1
+    x_ptr2.reset()
+    assert alloc_count == 1
+    assert dealloc_count == 1
+    
+    alloc_count = 0
+    dealloc_count = 0
+    cdef unique_ptr[CountAllocDealloc,FreePtr[CountAllocDealloc]] x_ptr3
+    x_ptr3.reset(new CountAllocDealloc(&alloc_count, &dealloc_count))
+    assert x_ptr3.get() != nullptr;
+    x_ptr3.reset()
+    assert x_ptr3.get() == nullptr;

tests/run/cpp_smart_ptr_helper.h

@@ -11,3 +11,14 @@ class CountAllocDealloc {
     int* _alloc_count;
     int* _dealloc_count;
 };
+
+template<typename T>
+struct FreePtr {
+  void operator()( T * t ) noexcept
+  {
+    if(t != nullptr) {
+      delete t;
+      t=nullptr;
+    }
+  }
+};