Testify examples.

Allow empty targets list in decl macro.
Update readme.
Fix `min_specialization`.

.github/workflows/rust.yml

@@ -22,6 +22,6 @@ jobs:
       - name: Build --all-features
         run: cargo build --verbose --all-features --all-targets
       - name: Run tests
-        run: cargo test --verbose
+        run: cargo test --verbose --lib --examples
       - name: Run tests --all-features
-        run: cargo test --verbose --all-features
+        run: cargo test --verbose --all-features --lib --examples

trait_cast_rs/examples/manual.rs

@@ -68,6 +68,7 @@ trait Cat: TraitcastableAny {
 }
 trait Mouse {}
 
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/manual_gen_struct.rs

@@ -73,6 +73,7 @@ impl<T: Display + 'static> TraitcastableAny for HybridPet<T> {
   }
 }
 
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/with_decl_macro.rs

@@ -42,7 +42,7 @@ trait Dog {
 trait Cat {
   fn meow(&self);
 }
-
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/with_decl_macro_gen.rs

@@ -35,7 +35,7 @@ trait Dog<T> {
 trait Cat<A, B> {
   fn meow(&self);
 }
-
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/with_decl_macro_gen_struct.rs

@@ -38,6 +38,7 @@ make_trait_castable_decl! {
   HybridPet<String> => (Dog, Cat<str>),
   HybridPet<u8> => (Dog, Cat<u128>),
 }
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/with_proc_macro.rs

@@ -33,7 +33,7 @@ trait Dog {
 trait Cat {
   fn meow(&self);
 }
-
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/with_proc_macro_enum.rs

@@ -35,7 +35,7 @@ trait Dog {
 trait Cat {
   fn meow(&self);
 }
-
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet::Name("Kokusnuss".to_string()));

trait_cast_rs/examples/with_proc_macro_gen.rs

@@ -34,7 +34,7 @@ trait Dog<T> {
 trait Cat<A, B> {
   fn meow(&self);
 }
-
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/examples/with_proc_macro_mut.rs

@@ -25,7 +25,7 @@ impl Dog for HybridPet {
 trait Dog {
   fn rename(&mut self, new_tag: String);
 }
-
+#[cfg_attr(test, test)]
 fn main() {
   // The box is technically not needed but kept for added realism
   let pet = Box::new(HybridPet {

trait_cast_rs/src/decl.rs

@@ -12,7 +12,7 @@
 /// ```
 #[macro_export]
 macro_rules! make_trait_castable_decl {
-  ($($source:ty => ($($target:path),+ $(,)?)),+$(,)?) => {
+  ($($source:ty => ($($target:path),* $(,)?)),+$(,)?) => {
     $(
       $(
         impl $crate::TraitcastableTo<dyn $target> for $source {
@@ -26,15 +26,21 @@ macro_rules! make_trait_castable_decl {
             casted.map(|selv| selv as &mut dyn $target)
           }
         }
-      )+
+      )*
       impl $crate::TraitcastableAny for $source {
         fn traitcast_targets(&self) -> &[$crate::TraitcastTarget] {
-          const TARGETS_LEN: usize = [$($crate::TraitcastTarget::from::<$source, dyn $target>(),)+].len();
+          const TARGETS_LEN: usize = {
+            let a:&[()] = &[$({
+              let _: &dyn $target;
+              ()
+            },)*];
+            a.len()
+          };
           const TARGETS: [$crate::TraitcastTarget; TARGETS_LEN] = {
             let mut targets = [
               $(
                 $crate::TraitcastTarget::from::<$source, dyn $target>(),
-              )+
+              )*
             ];
             $crate::maybe_sort!(targets);
             targets

trait_cast_rs/src/lib.rs

@@ -197,6 +197,7 @@ pub use trait_cast::*;
 
 mod decl;
 
+#[cfg(feature = "const_sort")]
 #[doc(hidden)]
 pub use const_sort_rs::ConstSliceSortExt;
 

trait_cast_rs/src/test.rs

@@ -2,6 +2,11 @@ pub use super::*;
 mod test {
   pub use super::*;
 
-  #[test]
-  fn test_wrong_source() {}
+  const fn _test_empty_trait_cast_targets() {
+    struct Woof {}
+
+    make_trait_castable_decl! {
+      Woof => (),
+    }
+  }
 }

trait_cast_rs/src/trait_cast.rs

@@ -185,8 +185,12 @@ impl<T: 'static> TraitcastableAny for T {
   default fn traitcast_targets(&self) -> &[TraitcastTarget] {
     &[]
   }
-  default unsafe fn find_traitcast_target(&self, _target: TypeId) -> Option<&TraitcastTarget> {
-    None
+  default unsafe fn find_traitcast_target(&self, target: TypeId) -> Option<&TraitcastTarget> {
+    // Note: copied from above
+    self
+      .traitcast_targets()
+      .iter()
+      .find(|possible| possible.target_type_id == target)
   }
 }
 impl Debug for dyn TraitcastableAny {