#2037 Option to optain declaration from early bound select definitions

src/ifcopenshell-python/ifcopenshell/express/implementation.py

@@ -55,6 +55,14 @@ class Implementation(codegen.Base):
                     templates.enum_from_string_stmt % dict(context, **locals()) for value in enum.values
                 ),
             )
+            
+        for name, enum in mapping.schema.selects.items():
+            write(
+                templates.select_function,
+                name=name,
+                schema_name=schema_name,
+                schema_name_upper=schema_name_upper
+            )
 
         write = lambda str, **kwargs: entity_implementations.append(str % kwargs)
 
@@ -348,6 +356,10 @@ class Implementation(codegen.Base):
                 ("extern enumeration_type* %s_%%s_type;" % schema_name_upper) % n
                 for n in mapping.schema.enumerations.keys()
             ]
+            + [
+                ("extern select_type* %s_%%s_type;" % schema_name_upper) % n
+                for n in mapping.schema.selects.keys()
+            ]
         )
 
         self.str = templates.implementation % {

src/ifcopenshell-python/ifcopenshell/express/templates.py

@@ -137,7 +137,10 @@ simpletype_impl_cast_templated = (
 simpletype_impl_declaration = "return *%(schema_name_upper)s_%(class_name)s_type;"
 
 select = """%(documentation)s
-class IFC_PARSE_API %(name)s : public virtual IfcUtil::IfcBaseInterface {};
+class IFC_PARSE_API %(name)s : public virtual IfcUtil::IfcBaseInterface {
+public:
+    static const IfcParse::select_type& Class();
+};
 """
 
 enumeration = """class IFC_PARSE_API %(name)s : public IfcUtil::IfcBaseType {
@@ -167,6 +170,10 @@ public:
 };
 """
 
+select_function = """
+const IfcParse::select_type& %(schema_name)s::%(name)s::Class() { return *%(schema_name_upper)s_%(name)s_type; }
+"""
+
 enumeration_function = """
 const IfcParse::enumeration_type& %(schema_name)s::%(name)s::declaration() const { return *%(schema_name_upper)s_%(name)s_type; }
 const IfcParse::enumeration_type& %(schema_name)s::%(name)s::Class() { return *%(schema_name_upper)s_%(name)s_type; }