A BuildableValue must be Sized

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/buildable.rs b/src/buildable.rs
index d1d2572..22f6d0a 100644
--- a/src/buildable.rs
+++ b/src/buildable.rs
@@ -2,7 +2,7 @@ use crate::ValueBuilder;
 use crate::Backend;
 
 // A value that can be built interactively, using a Backend
-pub trait BuildableValue {
+pub trait BuildableValue: Sized {
     fn builder<E, B>(backend: B) -> Box<dyn ValueBuilder<Output = Self, Error = E>>
         where E: Sized,
               B: Backend<Error = E>