I want a trait that enforces that two other traits must be met. Those two traits are derivable but Id like my wrapper trait to be derivable as well. What should I do? I want to avoid using macros as best as a I can.
#How to make a wrapper trait that surrounds two other derivable traits
solid night
stuck cape
making your trait derivable requires a derive macro
solid night
All my custom trait is a trait with zero function and just the requirement of self implementing two other traits
stuck cape
an alternative to derive macros would be a blanket impl, if you want the trait to always be implemented the same way for any type that has the supertraits
solid night
pub trait Syncable: Serialize + for<'a> Deserialize<'a> {}
then that sounds like you could use a blanket impl
crisp pumice
Ye, this sounds like it wants to be a trait alias, so a blanket impl will do
solid night
How do you write a blanket trait?
stuck cape
a blanket impl is like ```rs
impl<T> MyTrait for T {}
Would it function the same as what I want?
stuck cape
pretty much
any type that implements the other traits will then implement your trait
solid night
pub trait Syncable {}
impl<T> Syncable for T where T: Serialize + for<'a> Deserialize<'a> {}
So this ^^^
stuck cape
you should probably also have those other traits as supertraits of Syncable
solid night
so would this change work and be derivable?
stuck cape
no, you would not derive your trait
crisp pumice
so would this change work and be derivable?
it's still not derivable, you still need a macro for that, but it's no longer necessary
stuck cape
you wouldn't need to
crisp pumice
The trait is now automatically implemented in every possible case where you could derive it
It's already implemented
solid night
Oh ok
Now im getting this
the trait bound T: Deserialize<'_> is not satisfied
the trait Deserialize<'_> is not implemented for TrustcClick for full compiler diagnostic
lib.rs(179, 8): required by a bound in bincode::deserialize
convert.rs(15, 98): consider further restricting this bound: + serde::Deserialize<'_>
crisp pumice
the trait bound `T: Deserialize<'_>` is not satisfied
the trait `Deserialize<'_>...
Could you show the code you're getting this in?
solid night
/// Converts bytes into an object that implements serde Deserialize
pub fn struct_from_bytes<T>(bytes: &[u8]) -> Result<T, Box<bincode::ErrorKind>> where T: Syncable {
deserialize(bytes)
}
did you add the other traits as supertraits of Syncable?
solid night
How?
crisp pumice
did you add the other traits as supertraits of `Syncable`?
Like this
pub trait Syncable: Serialize + for<'a> Deserialize<'a> {}
like that
solid night
Okay now its fixed thanks
So whatever functions I add to the syncable trait will be applied to all objects that implement Serialize and De-serialize?
crisp pumice
Yup