struct Foo { field1: Type1, field2: Type2 }
let foo = Foo { field1: Type1::new(), field2: Type2::new() };
struct Bar ( Type1, Type2 ); // tuple type
let _ = Bar(Type1::new(), Type2::new());
struct Baz; // unit-like type
let _ = Baz;
let Foo { field1, .. } = foo; // extract field1 by pattern ...