BLI: support value initialization in CPPType

Value initialization differs from default-construction in that it
also zero-initializes trivial types.

1 files changed, 28 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_cpp_type.hh b/source/blender/blenlib/BLI_cpp_type.hh
index 881408f460b..8e8175c2265 100644
--- a/source/blender/blenlib/BLI_cpp_type.hh
+++ b/source/blender/blenlib/BLI_cpp_type.hh
@@ -110,6 +110,9 @@ class CPPType : NonCopyable, NonMovable {
   void (*default_construct_)(void *ptr) = nullptr;
   void (*default_construct_indices_)(void *ptr, IndexMask mask) = nullptr;
 
+  void (*value_initialize_)(void *ptr) = nullptr;
+  void (*value_initialize_indices_)(void *ptr, IndexMask mask) = nullptr;
+
   void (*destruct_)(void *ptr) = nullptr;
   void (*destruct_indices_)(void *ptr, IndexMask mask) = nullptr;
 
@@ -326,6 +329,31 @@ class CPPType : NonCopyable, NonMovable {
   }
 
   /**
+   * Same as #default_construct, but does zero initialization for trivial types.
+   *
+   * C++ equivalent:
+   *   new (ptr) T();
+   */
+  void value_initialize(void *ptr) const
+  {
+    BLI_assert(this->pointer_can_point_to_instance(ptr));
+
+    value_initialize_(ptr);
+  }
+
+  void value_initialize_n(void *ptr, int64_t n) const
+  {
+    this->value_initialize_indices(ptr, IndexMask(n));
+  }
+
+  void value_initialize_indices(void *ptr, IndexMask mask) const
+  {
+    BLI_assert(mask.size() == 0 || this->pointer_can_point_to_instance(ptr));
+
+    value_initialize_indices_(ptr, mask);
+  }
+
+  /**
    * Call the destructor on the given instance of this type. The pointer must not be nullptr.
    *
    * For some trivial types, this does nothing.