1
我有一个枚举与多个单字段元组结构变体。每个元组结构字段都是不同的结构。我想这样的代码:枚举结构变体的访问字段用一个元组结构包装
struct Foo { a: i32 }
struct Bar { b: i32 }
enum Foobar {
Foo(Foo),
Bar(Bar)
}
impl Foobar {
fn new_foo() -> Foobar {
Foobar::Foo(Foo { a: 1 })
}
fn new_bar() -> Foobar {
Foobar::Bar(Bar { b: 2 })
}
}
fn main() {
let x = vec![Foobar::new_foo(), Foobar::new_bar()];
let mut i = 0;
while i < x.len() {
let element = &x[i];
match element {
&Foobar::Foo(_) => { x[i].a = 3 },
&Foobar::Bar(_) => { x[i].b = 4 }
}
i += 1
}
}
编译器说:
error: attempted access of field
a
on typeFoobar
, but no field with that name was found
我试着在this question找到了解决方案,但它说:
error: cannot borrow immutable anonymous field as mutable
如何修改内容领域矢量x
?