Allow unions which are comparable to also be valid map keys (i.e. hashable)

1 files changed, 6 insertions, 0 deletions

diff --git a/src/check_type.cpp b/src/check_type.cpp
index aef1ddc7a..f70230682 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -2109,6 +2109,12 @@ void add_map_key_type_dependencies(CheckerContext *ctx, Type *key) {
 				Entity *field = key->Struct.fields[i];
 				add_map_key_type_dependencies(ctx, field->type);
 			}
+		} else if (key->kind == Type_Union) {
+			add_package_dependency(ctx, "runtime", "default_hasher_n");
+			for_array(i, key->Union.variants) {
+				Type *v = key->Union.variants[i];
+				add_map_key_type_dependencies(ctx, v);
+			}
 		} else if (key->kind == Type_EnumeratedArray) {
 			add_package_dependency(ctx, "runtime", "default_hasher_n");
 			add_map_key_type_dependencies(ctx, key->EnumeratedArray.elem);