--font-family CLI config

src/cli_args.zig

@@ -60,6 +60,8 @@ pub fn parse(comptime T: type, alloc: Allocator, dst: *T, iter: anytype) !void {
             try parseIntoField(T, arena_alloc, dst, key, value);
         }
     }
+
+    if (@hasDecl(T, "finalize")) try dst.finalize();
 }
 
 /// Parse a single key/value pair into the destination type T.
@@ -193,6 +195,28 @@ test "parse: simple" {
     try testing.expect(!data.@"b-f");
 }
 
+test "parse: finalize" {
+    const testing = std.testing;
+
+    var data: struct {
+        a: []const u8 = "",
+        _arena: ?ArenaAllocator = null,
+
+        pub fn finalize(self: *@This()) !void {
+            self.a = "YO";
+        }
+    } = .{};
+    defer if (data._arena) |arena| arena.deinit();
+
+    var iter = try std.process.ArgIteratorGeneral(.{}).init(
+        testing.allocator,
+        "--a=42",
+    );
+    defer iter.deinit();
+    try parse(@TypeOf(data), testing.allocator, &data, &iter);
+    try testing.expectEqualStrings("YO", data.a);
+}
+
 test "parseIntoField: string" {
     const testing = std.testing;
     var arena = ArenaAllocator.init(testing.allocator);