Trait apecs::TryDefault
source · [−]pub trait TryDefault: Sized {
fn try_default() -> Option<Self> { ... }
}
Expand description
Optional default creation.
This is used to attempt to create resources when they don’t already exist
in the world. See Read
and Write
.
This trait can be derived, so long as the type also has a Default
instance: ```rust
use apecs::*;
#[derive(Debug, Default, TryDefault, PartialEq)]
struct MyVec(Vec
assert_eq!(MyVec(vec![]), MyVec::try_default().unwrap());
The default implementation of `try_default` returns `None`:
```rust
use apecs::*;
#[derive(Debug, PartialEq)]
struct MyVec(Vec<String>);
impl TryDefault for MyVec {}
assert_eq!(None, MyVec::try_default());
Provided Methods
source