Add support for parsing standalone enum fields

examples/01_client_connect.zig

@@ -196,6 +196,11 @@ pub fn main() !void {
             std.debug.print("<- xdg_toplevel@{} {s} {}\n", .{ header.object_id, @tagName(@as(std.meta.Tag(wayland.xdg.Toplevel.Event), @enumFromInt(header.size_and_opcode.opcode))), std.zig.fmtEscapes(std.mem.sliceAsBytes(message_buffer.items)) });
         } else if (header.object_id == registry_done_id) {
             done = true;
+        } else if (header.object_id == shm_id) {
+            const event = try wayland.deserialize(wayland.core.Shm.Event, header, message_buffer.items);
+            switch (event) {
+                .format => |format| std.debug.print("<- format {} {}\n", .{ format.format, std.zig.fmtEscapes(std.mem.asBytes(&format.format)) }),
+            }
         } else if (header.object_id == 1) {
             const event = try wayland.deserialize(wayland.core.Display.Event, header, message_buffer.items);
             switch (event) {

src/core.zig

@@ -144,13 +144,10 @@ pub const Shm = struct {
         };
     };
 
-    pub const Event = union(Event.Tag) {
+    pub const Event = union(enum) {
-        format: Format,
+        format: struct {
-
+            format: Format,
-        pub const Tag = enum(u16) {
+        },
-            @"error",
-            delete_id,
-        };
     };
 
     pub const Format = enum(u32) {

src/main.zig

@@ -113,6 +113,11 @@ pub fn deserializeArguments(comptime Signature: type, buffer: []const u32) !Sign
                 .signed => @field(result, field.name) = try readInt(buffer, &pos),
                 .unsigned => @field(result, field.name) = try readUInt(buffer, &pos),
             },
+            .Enum => |enum_info| if (@sizeOf(enum_info.tag_type) == @sizeOf(u32)) {
+                @field(result, field.name) = @enumFromInt(try readInt(buffer, &pos));
+            } else {
+                @compileError("Unsupported type " ++ @typeName(field.type));
+            },
             .Pointer => |ptr| switch (ptr.size) {
                 .Slice => if (ptr.child == u8) {
                     @field(result, field.name) = try readString(buffer, &pos);