1  // Copyright (C) 2019-2025 ADnet Contributors
 2  // This file is part of the ADL library.
 3  
 4  // The ADL library is free software: you can redistribute it and/or modify
 5  // it under the terms of the GNU General Public License as published by
 6  // the Free Software Foundation, either version 3 of the License, or
 7  // (at your option) any later version.
 8  
 9  // The ADL library is distributed in the hope that it will be useful,
10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  // GNU General Public License for more details.
13  
14  // You should have received a copy of the GNU General Public License
15  // along with the ADL library. If not, see <https://www.gnu.org/licenses/>.
16  
17  use crate::Type;
18  
19  use serde::{Deserialize, Serialize};
20  use std::fmt;
21  
22  /// An optional type. For example `u32?` where `inner` refers to `u32`.
23  #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
24  pub struct OptionalType {
25      pub inner: Box<Type>,
26  }
27  
28  impl fmt::Display for OptionalType {
29      fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
30          write!(f, "{}?", self.inner)
31      }
32  }