Unregister render object constructors gracefully (#4993)

Author: oitel

source/MRMesh/MRIRenderObject.cpp

@@ -20,6 +20,11 @@ class RenderObjectConstructorsHolder
         auto& inst = instance_();
         inst.map_[type] = lambda;
     }
+    static void removeConstructorLambda( const std::type_index& type )
+    {
+        auto& inst = instance_();
+        inst.map_.erase( type );
+    }
 private:
     static RenderObjectConstructorsHolder& instance_()
     {
@@ -31,10 +36,16 @@ class RenderObjectConstructorsHolder
 
 
 RegisterRenderObjectConstructor::RegisterRenderObjectConstructor( const std::type_index& type, IRenderObjectConstructorLambda lambda )
+    : type_( type )
 {
     RenderObjectConstructorsHolder::addConstructorLambda( type, lambda );
 }
 
+RegisterRenderObjectConstructor::~RegisterRenderObjectConstructor()
+{
+    RenderObjectConstructorsHolder::removeConstructorLambda( type_ );
+}
+
 std::unique_ptr<IRenderObject> createRenderObject( const VisualObject& visObj, const std::type_index& type )
 {
     auto lambda = RenderObjectConstructorsHolder::findConstructorLambda( type );

source/MRMesh/MRIRenderObject.h

@@ -208,6 +208,10 @@ class RegisterRenderObjectConstructor
 {
 public:
     MRMESH_API RegisterRenderObjectConstructor( const std::type_index& type, IRenderObjectConstructorLambda lambda );
+    MRMESH_API ~RegisterRenderObjectConstructor();
+
+private:
+    std::type_index type_;
 };
 
 #define MR_REGISTER_RENDER_OBJECT_IMPL(objectType, .../*rendObjectType*/)\