started implementing declare_dynamic

1) Removed socket storage allocation in initfunc_api function.

2) Replaced manual free and copy functions for rlayer node , with
   node_free_standard_storage() and node_copy_standard_storage().

3) Removed the socket creation code that was shared with the Image node.

4) RenderLayersNode::test_render_link() now uses socket identifiers
   instead of socket storage to check socket types.

5) NodeImageLayer structure is no longer used as socket storage data.

@@ -688,0 +695,4 @@
+                                          eNodeSocketDatatype type)
+{
+  NodeDeclarationBuilder *builder = static_cast<NodeDeclarationBuilder*>(userdata); 
+  if(std::string(name) != std::string(RE_PASSNAME_COMBINED)){

@@ -688,0 +698,4 @@
+  if(std::string(name) != std::string(RE_PASSNAME_COMBINED)){
+    switch(type){
+      case SOCK_FLOAT:
+        builder->add_output<decl::Float>(name);

@@ -688,0 +717,4 @@
+  NodeDeclarationBuilder builder(r_declaration); 
+  builder.add_output<decl::Color>("Image"); 
+  builder.add_output<decl::Float>("Alpha");
+  if(scene){

@@ -788,3 +831,3 @@
   row = uiLayoutRow(col, true);
   uiItemR(row, ptr, "layer", UI_ITEM_R_SPLIT_EMPTY_NAME, "", ICON_NONE);
-
+  

@@ -61,1 +61,3 @@
-    NodeImageLayer *storage = (NodeImageLayer *)output->get_bnode_socket()->storage;
+    const char *socket_identifier = output->get_bnode_socket()->identifier;
+    if (strstr(socket_identifier, "Combined")) {
+      socket_identifier = "Combined";

@@ -70,2 +73,3 @@
     if (STREQ(rpass->name, RE_PASSNAME_COMBINED) &&
-        STREQ(output->get_bnode_socket()->name, "Alpha")) {
+        STREQ(output->get_bnode_socket()->name, "Alpha"))
+    {

@@ -913,3 +812,3 @@
 
   cmp_node_type_base(&ntype, CMP_NODE_R_LAYERS, "Render Layers", NODE_CLASS_INPUT);
-  blender::bke::node_type_socket_templates(&ntype, nullptr, cmp_node_rlayers_out);
+  ntype.declare_dynamic = file_ns::node_rlayer_declare_dynamic;

@@ -701,7 +576,7 @@ void register_node_type_cmp_image()
 
 void node_cmp_rlayers_outputs(bNodeTree *ntree, bNode *node)

@@ -719,0 +603,4 @@
+  if (!STREQ(name, RE_PASSNAME_COMBINED)) {
+    switch (type) {
+      case SOCK_FLOAT:
+        builder->add_output<decl::Float>(name);

@@ -953,8 +851,6 @@ void register_node_type_cmp_rlayers()
   ntype.flag |= NODE_PREVIEW;
   node_type_storage(
       &ntype, nullptr, file_ns::node_composit_free_rlayers, file_ns::node_composit_copy_rlayers);

@@ -338,3 +218,2 @@
 /* XXX make this into a generic socket verification function for dynamic socket replacement
- * (multi-layer, groups, static templates). */
-static void cmp_node_image_verify_outputs(bNodeTree *ntree, bNode *node, bool rlayer)
+ * (multi-layer, groups, static templates) */

@@ -342,4 +222,4 @@
   bNodeSocket *sock, *sock_next;
   LinkNodePair available_sockets = {nullptr, nullptr};
 
   /* XXX make callback */

@@ -558,0 +444,4 @@
+
+static void node_rlayer_declare(NodeDeclarationBuilder &builder)
+{
+  builder.add_output<decl::Color>("Image");