[core] Render fill-extrusion layers (#8431)

1 files changed, 40 insertions, 0 deletions

diff --git a/include/mbgl/util/type_list.hpp b/include/mbgl/util/type_list.hpp
new file mode 100644
index 0000000000..4a5e95c8a4
--- /dev/null
+++ b/include/mbgl/util/type_list.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <type_traits>
+#include <tuple>
+
+namespace mbgl {
+
+template <class...>
+class TypeList {};
+
+namespace detail {
+
+template <class, class>
+struct TypeCons;
+
+template <class T, class... Ts>
+struct TypeCons<T, TypeList<Ts...>> {
+    using Type = TypeList<T, Ts...>;
+};
+
+template <class, template <class> class>
+struct TypeFilter;
+
+template <template <class> class Predicate>
+struct TypeFilter<TypeList<>, Predicate> {
+    using Type = TypeList<>;
+};
+
+template <template <class> class Predicate, class T, class... Ts>
+struct TypeFilter<TypeList<T, Ts...>, Predicate> {
+    using Tail = typename TypeFilter<TypeList<Ts...>, Predicate>::Type;
+    using Type = std::conditional_t<Predicate<T>::value, typename TypeCons<T, Tail>::Type, Tail>;
+};
+
+} // namespace detail
+
+template <class TypeList, template <class> class Predicate>
+using FilteredTypeList = typename detail::TypeFilter<TypeList, Predicate>::Type;
+
+} // namespace mbgl