Add Debug implementation

Signed-off-by: trivernis <trivernis@protonmail.com>

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "multi-trait-object"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 readme = "README.md"
 license = "Apache-2.0"

src/lib.rs

@@ -4,7 +4,10 @@ mod tests;
 
 pub(crate) mod macros;
 mod trait_impl;
+mod std_impl;
+
 pub use trait_impl::*;
+pub use std_impl::*;
 
 use std::any::{Any, TypeId};
 use std::collections::HashMap;
@@ -33,7 +36,6 @@ pub struct FatPointer {
 /// let string = mto.downcast::<String>().unwrap();
 /// println!("{}", string);
 /// ```
-#[derive(Debug)]
 pub struct MultitraitObject {
     pub(crate) data: *mut (),
     pub(crate) original_typeid: TypeId,

src/std_impl.rs

@@ -0,0 +1,6 @@
+use std::fmt::{Debug, Display};
+use std::fmt::Write as FmtWrite;
+
+use crate::*;
+
+impl_trait_object!(String, dyn Debug, dyn Display, dyn RawClone, dyn FmtWrite);

src/tests.rs

@@ -41,6 +41,7 @@ fn it_creates_fat_pointers() {
 #[test]
 fn it_constructs() {
     TestStruct::default().into_multitrait();
+    String::from("test").into_multitrait();
 }
 
 #[test]

src/trait_impl/debug.rs

@@ -0,0 +1,12 @@
+use std::fmt::{Debug, Formatter};
+use crate::MultitraitObject;
+
+impl Debug for MultitraitObject {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        if let Some(debug) = self.downcast_trait::<dyn Debug>() {
+            debug.fmt(f)
+        } else {
+            write!(f, "<unavailable>")
+        }
+    }
+}

src/trait_impl/mod.rs

@@ -1,2 +1,5 @@
 mod try_clone;
+mod debug;
+
 pub use try_clone::*;
+pub use debug::*;

src/trait_impl/try_clone.rs

@@ -27,6 +27,8 @@ impl TryClone for MultitraitObject {
     fn try_clone(&self) -> Option<Self> {
         let clone = self.downcast_trait::<dyn RawClone>()?;
         let data_ptr = unsafe {
+            // SAFETY: We're using the pointer in the multitrait object so
+            // it won't leak memory
             clone.raw_clone()
         };
         Some(MultitraitObject {