make SingularRobust default

src/rstd/singular.rs

@@ -21,10 +21,6 @@ pub struct SingularResolver<'a, Ctx: Context<'a>> {
     points: Vec<Arc<dyn SingularResolution<'a, Ctx>>>,
 }
 
-struct SingularRobust<'a, Ctx: Context<'a>> {
-    resolver: Arc<SingularResolver<'a, Ctx>>,
-}
-
 impl<'a, Ctx: Context<'a>> SingularResolver<'a, Ctx> {
     pub fn from_mentionable<A: Mentionable<'a, Ctx>>(a: &A) -> Self {
         let mut points = Vec::new();
@@ -53,26 +49,11 @@ impl<'a, Ctx: Context<'a>> SingularResolver<'a, Ctx> {
             Ok(point.clone().singular())
         }
     }
-
-    pub fn robust(self) -> Arc<dyn Resolver<'a, Ctx>> {
-        SingularRobust {
-            resolver: self.into(),
-        }
-        .into_rc()
-    }
 }
 
 impl<'a, Ctx: Context<'a>> Resolver<'a, Ctx> for SingularResolver<'a, Ctx> {
     fn resolve(self: Arc<Self>, address: Address) -> HashResolution<'a, Ctx> {
-        self.resolve_robust(address).unwrap()
-    }
-}
-
-impl<'a, Ctx: Context<'a>> Resolver<'a, Ctx> for SingularRobust<'a, Ctx> {
-    fn resolve(self: Arc<Self>, address: Address) -> HashResolution<'a, Ctx> {
-        self.resolver
-            .clone()
-            .resolve_robust(address)
+        self.resolve_robust(address)
             .map_err(SingularError::into)
             .map_err(Err)
             .unwrap_or_else(Ctx::pure)

src/rstd/tcast.rs

@@ -8,7 +8,7 @@ pub trait CastMentionable<'a, Ctx: Context<'a>>: Mentionable<'a, Ctx> {
     fn m_cast<A: Mentionable<'a, Ctx>>(&self, factory: &Fctr<'a, A>) -> ParseResultA<'a, A> {
         factory.parse_slice(
             &self.bytes(),
-            &SingularResolver::from_mentionable(self).robust(),
+            &SingularResolver::from_mentionable(self).into_rc(),
         )
     }
 }