# Compile structures used to map tagged primitive values to their classes and types.
	# This method also determines which class will be tagged.
	fun compile_class_infos
	do
		if modelbuilder.toolcontext.opt_no_tag_primitives.value then return

		# Note: if you change the tagging scheme, do not forget to update
		# `autobox` and `extract_tag`
		var class_info = new Array[nullable MClass].filled_with(null, 4)
		for t in box_kinds.keys do
			# Note: a same class can be associated to multiple slots if one want to
			# use some Huffman coding.
			if t.name == "Int" then
				class_info[1] = t
				t.mclass_type.tag_value = 1
			else if t.name == "Char" then
				class_info[2] = t
				t.mclass_type.tag_value = 2
			else if t.name == "Bool" then
				class_info[3] = t
				t.mclass_type.tag_value = 3
			else
				continue
			end
			t.mclass_type.is_tagged = true
		end

		# Compile the table for classes. The tag is used as an index
		var v = self.new_visitor
		v.add_decl "const struct class *class_info[4] = \{"
		for t in class_info do
			if t == null then
				v.add_decl("NULL,")
			else
				var s = "class_{t.c_name}"
				v.require_declaration(s)
				v.add_decl("&{s},")
			end
		end
		v.add_decl("\};")

		# Compile the table for types. The tag is used as an index
		v.add_decl "const struct type *type_info[4] = \{"
		for t in class_info do
			if t == null then
				v.add_decl("NULL,")
			else
				var s = "type_{t.c_name}"
				undead_types.add(t.mclass_type)
				v.require_declaration(s)
				v.add_decl("&{s},")
			end
		end
		v.add_decl("\};")
	end