Add `struct #simple` to force a struct to use simple comparison if all of the fields "nearly simply comparable".

1 files changed, 15 insertions, 0 deletions

diff --git a/src/check_type.cpp b/src/check_type.cpp
index 4b8f7b6ac..41c5f48d1 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -679,6 +679,21 @@ gb_internal void check_struct_type(CheckerContext *ctx, Type *struct_type, Ast *
 			gb_unused(where_clause_ok);
 		}
 		check_struct_fields(ctx, node, &struct_type->Struct.fields, &struct_type->Struct.tags, st->fields, min_field_count, struct_type, context);
+
+		if (st->is_simple) {
+			bool success = true;
+			for (Entity *f : struct_type->Struct.fields) {
+				if (!is_type_nearly_simple_compare(f->type)) {
+					gbString s = type_to_string(f->type);
+					error(f->token, "'struct #simple' requires all fields to be at least 'nearly simple compare', got %s", s);
+					gb_string_free(s);
+				}
+			}
+			if (success) {
+				struct_type->Struct.is_simple = true;
+			}
+		}
+
 		wait_signal_set(&struct_type->Struct.fields_wait_signal);
 	}