feat: add DI container

19 files changed, 1307 insertions, 1 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 1717a29..a0e6dd9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,6 @@
 [workspace]
 members = [
 	"syrette",
-	"syrette_macros"
+	"syrette_macros",
+	"example",
 ]
diff --git a/syrette/Cargo.toml b/syrette/Cargo.toml
index 378a243..6575ef1 100644
--- a/syrette/Cargo.toml
+++ b/syrette/Cargo.toml
@@ -7,3 +7,8 @@ description = "The convenient dependency injection library"
 edition = "2021"
 
 [dependencies]
+syrette_macros = { path = "../syrette_macros" }
+linkme = "0.3.0"
+once_cell = "1.4"
+error-stack = "0.1.1"
+
diff --git a/syrette/src/di_container.rs b/syrette/src/di_container.rs
new file mode 100644
index 0000000..ce0d829
--- /dev/null
+++ b/syrette/src/di_container.rs
@@ -0,0 +1,161 @@
+use std::any::{type_name, TypeId};
+use std::collections::HashMap;
+use std::fmt;
+use std::fmt::{Display, Formatter};
+use std::marker::PhantomData;
+use std::rc::Rc;
+
+use error_stack::{Context, Report, ResultExt};
+
+use crate::injectable::{Injectable, ResolveError};
+use crate::libs::intertrait::cast_box::CastBox;
+
+trait IInjectableTypeProvider
+{
+    fn provide(
+        &self,
+        di_container: &DIContainer,
+    ) -> error_stack::Result<Box<dyn Injectable>, ResolveError>;
+}
+
+struct InjectableTypeProvider<InjectableType>
+where
+    InjectableType: Injectable,
+{
+    _phantom_data: PhantomData<InjectableType>,
+}
+
+impl<InjectableType> InjectableTypeProvider<InjectableType>
+where
+    InjectableType: Injectable,
+{
+    fn new() -> Self
+    {
+        Self {
+            _phantom_data: PhantomData,
+        }
+    }
+}
+
+impl<InjectableType> IInjectableTypeProvider for InjectableTypeProvider<InjectableType>
+where
+    InjectableType: Injectable,
+{
+    fn provide(
+        &self,
+        di_container: &DIContainer,
+    ) -> error_stack::Result<Box<dyn Injectable>, ResolveError>
+    {
+        Ok(InjectableType::resolve(di_container)?)
+    }
+}
+
+pub struct BindingBuilder<'a, InterfaceTrait>
+where
+    InterfaceTrait: 'static + ?Sized,
+{
+    _di_container: &'a mut DIContainer,
+    _phantom_data: PhantomData<InterfaceTrait>,
+}
+
+impl<'a, InterfaceTrait> BindingBuilder<'a, InterfaceTrait>
+where
+    InterfaceTrait: 'static + ?Sized,
+{
+    fn new(di_container: &'a mut DIContainer) -> Self
+    {
+        Self {
+            _di_container: di_container,
+            _phantom_data: PhantomData,
+        }
+    }
+
+    pub fn to<Implementation>(&mut self)
+    where
+        Implementation: Injectable,
+    {
+        let interface_typeid = TypeId::of::<InterfaceTrait>();
+
+        self._di_container._bindings.insert(
+            interface_typeid,
+            Rc::new(InjectableTypeProvider::<Implementation>::new()),
+        );
+    }
+}
+
+#[derive(Debug)]
+pub struct DIContainerError;
+
+impl Display for DIContainerError
+{
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result
+    {
+        fmt.write_str("A DI container error has occurred")
+    }
+}
+
+impl Context for DIContainerError {}
+
+pub struct DIContainer
+{
+    _bindings: HashMap<TypeId, Rc<dyn IInjectableTypeProvider>>,
+}
+
+impl<'a> DIContainer
+{
+    pub fn new() -> Self
+    {
+        Self {
+            _bindings: HashMap::new(),
+        }
+    }
+
+    pub fn bind<InterfaceTrait>(&'a mut self) -> BindingBuilder<InterfaceTrait>
+    where
+        InterfaceTrait: 'static + ?Sized,
+    {
+        BindingBuilder::<InterfaceTrait>::new(self)
+    }
+
+    pub fn get<InterfaceTrait>(
+        &self,
+    ) -> error_stack::Result<Box<InterfaceTrait>, DIContainerError>
+    where
+        InterfaceTrait: 'static + ?Sized,
+    {
+        let interface_typeid = TypeId::of::<InterfaceTrait>();
+
+        let interface_name = type_name::<InterfaceTrait>();
+
+        let binding = self._bindings.get(&interface_typeid).ok_or_else(|| {
+            Report::new(DIContainerError)
+                .attach_printable(format!("No binding exists for {}", interface_name))
+        })?;
+
+        let binding_injectable = binding
+            .provide(self)
+            .change_context(DIContainerError)
+            .attach_printable(format!(
+            "Failed to resolve interface {}",
+            interface_name
+        ))?;
+
+        let interface_box_result = binding_injectable.cast::<InterfaceTrait>();
+
+        match interface_box_result {
+            Ok(interface_box) => Ok(interface_box),
+            Err(_) => Err(Report::new(DIContainerError).attach_printable(format!(
+                "Unable to cast binding for {}",
+                interface_name
+            ))),
+        }
+    }
+}
+
+impl Default for DIContainer
+{
+    fn default() -> Self
+    {
+        Self::new()
+    }
+}
diff --git a/syrette/src/injectable.rs b/syrette/src/injectable.rs
new file mode 100644
index 0000000..3cc0d7f
--- /dev/null
+++ b/syrette/src/injectable.rs
@@ -0,0 +1,29 @@
+use core::fmt;
+use std::fmt::{Display, Formatter};
+
+use error_stack::Context;
+
+use crate::libs::intertrait::CastFrom;
+use crate::DIContainer;
+
+#[derive(Debug)]
+pub struct ResolveError;
+
+impl Display for ResolveError
+{
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result
+    {
+        fmt.write_str("Failed to resolve injectable struct")
+    }
+}
+
+impl Context for ResolveError {}
+
+pub trait Injectable: CastFrom
+{
+    fn resolve(
+        di_container: &DIContainer,
+    ) -> error_stack::Result<Box<Self>, ResolveError>
+    where
+        Self: Sized;
+}
diff --git a/syrette/src/lib.rs b/syrette/src/lib.rs
index e69de29..5cf9f71 100644
--- a/syrette/src/lib.rs
+++ b/syrette/src/lib.rs
@@ -0,0 +1,8 @@
+mod di_container;
+
+pub use di_container::*;
+pub use syrette_macros::*;
+
+pub mod injectable;
+
+pub mod libs;
diff --git a/syrette/src/libs/intertrait/LICENSE-APACHE b/syrette/src/libs/intertrait/LICENSE-APACHE
new file mode 100644
index 0000000..d9a10c0
--- /dev/null
+++ b/syrette/src/libs/intertrait/LICENSE-APACHE
@@ -0,0 +1,176 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
diff --git a/syrette/src/libs/intertrait/LICENSE-MIT b/syrette/src/libs/intertrait/LICENSE-MIT
new file mode 100644
index 0000000..969d061
--- /dev/null
+++ b/syrette/src/libs/intertrait/LICENSE-MIT
@@ -0,0 +1,17 @@
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/syrette/src/libs/intertrait/cast_box.rs b/syrette/src/libs/intertrait/cast_box.rs
new file mode 100644
index 0000000..d4da740
--- /dev/null
+++ b/syrette/src/libs/intertrait/cast_box.rs
@@ -0,0 +1,32 @@
+/**
+ * Originally from Intertrait by CodeChain
+ *
+ * https://github.com/CodeChain-io/intertrait
+ * https://crates.io/crates/intertrait/0.2.2
+ *
+ * Licensed under either of
+ *
+ * Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
+
+ * at your option.
+*/
+use crate::libs::intertrait::{caster, CastFrom};
+
+pub trait CastBox
+{
+    /// Casts a box to this trait into that of type `T`. If fails, returns the receiver.
+    fn cast<T: ?Sized + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Self>>;
+}
+
+/// A blanket implementation of `CastBox` for traits extending `CastFrom`.
+impl<S: ?Sized + CastFrom> CastBox for S
+{
+    fn cast<T: ?Sized + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Self>>
+    {
+        match caster::<T>((*self).type_id()) {
+            Some(caster) => Ok((caster.cast_box)(self.box_any())),
+            None => Err(self),
+        }
+    }
+}
diff --git a/syrette/src/libs/intertrait/hasher.rs b/syrette/src/libs/intertrait/hasher.rs
new file mode 100644
index 0000000..1fe7739
--- /dev/null
+++ b/syrette/src/libs/intertrait/hasher.rs
@@ -0,0 +1,44 @@
+/**
+ * Originally from Intertrait by CodeChain
+ *
+ * https://github.com/CodeChain-io/intertrait
+ * https://crates.io/crates/intertrait/0.2.2
+ *
+ * Licensed under either of
+ *
+ * Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
+
+ * at your option.
+*/
+use std::convert::TryInto;
+use std::hash::{BuildHasherDefault, Hasher};
+use std::mem::size_of;
+
+/// A simple `Hasher` implementation tuned for performance.
+#[derive(Default)]
+pub struct FastHasher(u64);
+
+/// A `BuildHasher` for `FastHasher`.
+pub type BuildFastHasher = BuildHasherDefault<FastHasher>;
+
+impl Hasher for FastHasher
+{
+    fn finish(&self) -> u64
+    {
+        self.0
+    }
+
+    fn write(&mut self, bytes: &[u8])
+    {
+        let mut bytes = bytes;
+        while bytes.len() > size_of::<u64>() {
+            let (u64_bytes, remaining) = bytes.split_at(size_of::<u64>());
+            self.0 ^= u64::from_ne_bytes(u64_bytes.try_into().unwrap());
+            bytes = remaining
+        }
+        self.0 ^= bytes
+            .iter()
+            .fold(0u64, |result, b| (result << 8) | *b as u64);
+    }
+}
diff --git a/syrette/src/libs/intertrait/mod.rs b/syrette/src/libs/intertrait/mod.rs
new file mode 100644
index 0000000..b07d91e
--- /dev/null
+++ b/syrette/src/libs/intertrait/mod.rs
@@ -0,0 +1,221 @@
+/**
+ * Originally from Intertrait by CodeChain
+ *
+ * https://github.com/CodeChain-io/intertrait
+ * https://crates.io/crates/intertrait/0.2.2
+ *
+ * Licensed under either of
+ *
+ * Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
+
+ * at your option.
+*/
+use std::any::{Any, TypeId};
+use std::collections::HashMap;
+use std::rc::Rc;
+use std::sync::Arc;
+
+use once_cell::sync::Lazy;
+
+extern crate linkme;
+
+pub use syrette_macros::castable_to;
+
+mod hasher;
+
+use hasher::BuildFastHasher;
+
+pub mod cast_box;
+
+pub type BoxedCaster = Box<dyn Any + Send + Sync>;
+
+#[linkme::distributed_slice]
+pub static CASTERS: [fn() -> (TypeId, BoxedCaster)] = [..];
+
+static CASTER_MAP: Lazy<HashMap<(TypeId, TypeId), BoxedCaster, BuildFastHasher>> =
+    Lazy::new(|| {
+        CASTERS
+            .iter()
+            .map(|f| {
+                let (type_id, caster) = f();
+                ((type_id, (*caster).type_id()), caster)
+            })
+            .collect()
+    });
+
+pub struct Caster<T: ?Sized + 'static>
+{
+    /// Casts an immutable reference to a trait object for `Any` to a reference
+    /// to a trait object for trait `T`.
+    pub cast_ref: fn(from: &dyn Any) -> &T,
+
+    /// Casts a mutable reference to a trait object for `Any` to a mutable reference
+    /// to a trait object for trait `T`.
+    pub cast_mut: fn(from: &mut dyn Any) -> &mut T,
+
+    /// Casts a `Box` holding a trait object for `Any` to another `Box` holding a trait object
+    /// for trait `T`.
+    pub cast_box: fn(from: Box<dyn Any>) -> Box<T>,
+
+    /// Casts an `Rc` holding a trait object for `Any` to another `Rc` holding a trait object
+    /// for trait `T`.
+    pub cast_rc: fn(from: Rc<dyn Any>) -> Rc<T>,
+}
+
+impl<T: ?Sized + 'static> Caster<T>
+{
+    pub fn new(
+        cast_ref: fn(from: &dyn Any) -> &T,
+        cast_mut: fn(from: &mut dyn Any) -> &mut T,
+        cast_box: fn(from: Box<dyn Any>) -> Box<T>,
+        cast_rc: fn(from: Rc<dyn Any>) -> Rc<T>,
+    ) -> Caster<T>
+    {
+        Caster::<T> {
+            cast_ref,
+            cast_mut,
+            cast_box,
+            cast_rc,
+        }
+    }
+
+    pub fn new_sync(
+        cast_ref: fn(from: &dyn Any) -> &T,
+        cast_mut: fn(from: &mut dyn Any) -> &mut T,
+        cast_box: fn(from: Box<dyn Any>) -> Box<T>,
+        cast_rc: fn(from: Rc<dyn Any>) -> Rc<T>,
+    ) -> Caster<T>
+    {
+        Caster::<T> {
+            cast_ref,
+            cast_mut,
+            cast_box,
+            cast_rc,
+        }
+    }
+}
+
+/// Returns a `Caster<S, T>` from a concrete type `S` to a trait `T` implemented by it.
+fn caster<T: ?Sized + 'static>(type_id: TypeId) -> Option<&'static Caster<T>>
+{
+    CASTER_MAP
+        .get(&(type_id, TypeId::of::<Caster<T>>()))
+        .and_then(|caster| caster.downcast_ref::<Caster<T>>())
+}
+
+/// `CastFrom` must be extended by a trait that wants to allow for casting into another trait.
+///
+/// It is used for obtaining a trait object for [`Any`] from a trait object for its sub-trait,
+/// and blanket implemented for all `Sized + Any + 'static` types.
+///
+/// # Examples
+/// ```ignore
+/// trait Source: CastFrom {
+///     ...
+/// }
+/// ```
+pub trait CastFrom: Any + 'static
+{
+    /// Returns a immutable reference to `Any`, which is backed by the type implementing this trait.
+    fn ref_any(&self) -> &dyn Any;
+
+    /// Returns a mutable reference to `Any`, which is backed by the type implementing this trait.
+    fn mut_any(&mut self) -> &mut dyn Any;
+
+    /// Returns a `Box` of `Any`, which is backed by the type implementing this trait.
+    fn box_any(self: Box<Self>) -> Box<dyn Any>;
+
+    /// Returns an `Rc` of `Any`, which is backed by the type implementing this trait.
+    fn rc_any(self: Rc<Self>) -> Rc<dyn Any>;
+}
+
+pub trait CastFromSync: CastFrom + Sync + Send + 'static
+{
+    fn arc_any(self: Arc<Self>) -> Arc<dyn Any + Sync + Send + 'static>;
+}
+
+impl<T: Sized + Any + 'static> CastFrom for T
+{
+    fn ref_any(&self) -> &dyn Any
+    {
+        self
+    }
+
+    fn mut_any(&mut self) -> &mut dyn Any
+    {
+        self
+    }
+
+    fn box_any(self: Box<Self>) -> Box<dyn Any>
+    {
+        self
+    }
+
+    fn rc_any(self: Rc<Self>) -> Rc<dyn Any>
+    {
+        self
+    }
+}
+
+impl CastFrom for dyn Any + 'static
+{
+    fn ref_any(&self) -> &dyn Any
+    {
+        self
+    }
+
+    fn mut_any(&mut self) -> &mut dyn Any
+    {
+        self
+    }
+
+    fn box_any(self: Box<Self>) -> Box<dyn Any>
+    {
+        self
+    }
+
+    fn rc_any(self: Rc<Self>) -> Rc<dyn Any>
+    {
+        self
+    }
+}
+
+impl<T: Sized + Sync + Send + 'static> CastFromSync for T
+{
+    fn arc_any(self: Arc<Self>) -> Arc<dyn Any + Sync + Send + 'static>
+    {
+        self
+    }
+}
+
+impl CastFrom for dyn Any + Sync + Send + 'static
+{
+    fn ref_any(&self) -> &dyn Any
+    {
+        self
+    }
+
+    fn mut_any(&mut self) -> &mut dyn Any
+    {
+        self
+    }
+
+    fn box_any(self: Box<Self>) -> Box<dyn Any>
+    {
+        self
+    }
+
+    fn rc_any(self: Rc<Self>) -> Rc<dyn Any>
+    {
+        self
+    }
+}
+
+impl CastFromSync for dyn Any + Sync + Send + 'static
+{
+    fn arc_any(self: Arc<Self>) -> Arc<dyn Any + Sync + Send + 'static>
+    {
+        self
+    }
+}
diff --git a/syrette/src/libs/mod.rs b/syrette/src/libs/mod.rs
new file mode 100644
index 0000000..8d5583d
--- /dev/null
+++ b/syrette/src/libs/mod.rs
@@ -0,0 +1,3 @@
+pub mod intertrait;
+
+pub extern crate linkme;
diff --git a/syrette_macros/Cargo.toml b/syrette_macros/Cargo.toml
index 0d72785..a6966f0 100644
--- a/syrette_macros/Cargo.toml
+++ b/syrette_macros/Cargo.toml
@@ -6,4 +6,12 @@ authors = ["HampusM <hampus@hampusmat.com>"]
 description = "Macros for Syrette, the convenient dependency injection library"
 edition = "2021"
 
+[lib]
+proc_macro = true
+
 [dependencies]
+syn = { version = "1.0.96", features = ["full"] }
+quote = "1.0.18"
+proc-macro2 = "1.0.40"
+uuid = { version = "0.8", features = ["v4"] }
+
diff --git a/syrette_macros/src/lib.rs b/syrette_macros/src/lib.rs
index e69de29..3fd8a59 100644
--- a/syrette_macros/src/lib.rs
+++ b/syrette_macros/src/lib.rs
@@ -0,0 +1,221 @@
+use proc_macro::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{
+    parse, parse_macro_input, parse_str, punctuated::Punctuated, token::Comma,
+    AttributeArgs, FnArg, GenericArgument, ImplItem, ItemImpl, Meta, NestedMeta, Path,
+    PathArguments, Type, TypePath,
+};
+
+mod libs;
+
+use libs::intertrait_macros::{
+    args::{Casts, Flag, Targets},
+    gen_caster::generate_caster,
+};
+
+const NO_INTERFACE_ARG_ERR_MESSAGE: &str =
+    "Expected a argument specifying a interface trait";
+
+const INVALID_ARG_ERR_MESSAGE: &str = "Invalid argument passed";
+
+const INVALID_ITEM_TYPE_ERR_MESSAGE: &str =
+    "The attached to item is not a trait implementation";
+
+const IMPL_NO_NEW_METHOD_ERR_MESSAGE: &str =
+    "The attached to trait implementation is missing a new method";
+
+const IMPL_NEW_METHOD_SELF_PARAM_ERR_MESSAGE: &str =
+    "The new method of the attached to trait implementation cannot have a self parameter";
+
+const IMPL_NEW_METHOD_BOX_PARAMS_ERR_MESSAGE: &str =
+    "All parameters of the new method of the attached to trait implementation must be std::boxed::Box";
+
+fn path_to_string(path: &Path) -> String
+{
+    return path
+        .segments
+        .pairs()
+        .fold(String::new(), |mut acc, segment_pair| {
+            let segment_ident = &segment_pair.value().ident;
+
+            acc.push_str(segment_ident.to_string().as_str());
+
+            let opt_colon_two = segment_pair.punct();
+
+            match opt_colon_two {
+                Some(colon_two) => {
+                    acc.push_str(colon_two.to_token_stream().to_string().as_str())
+                }
+                None => {}
+            }
+
+            acc
+        });
+}
+
+fn get_fn_args_has_self(fn_args: &Punctuated<FnArg, Comma>) -> bool
+{
+    return fn_args.iter().any(|arg| match arg {
+        FnArg::Receiver(_) => true,
+        &_ => false,
+    });
+}
+
+fn get_fn_arg_type_paths(fn_args: &Punctuated<FnArg, Comma>) -> Vec<TypePath>
+{
+    return fn_args.iter().fold(Vec::<TypePath>::new(), |mut acc, arg| {
+        match arg {
+            FnArg::Typed(typed_fn_arg) => match typed_fn_arg.ty.as_ref() {
+                Type::Path(arg_type_path) => acc.push(arg_type_path.clone()),
+                &_ => {}
+            },
+            FnArg::Receiver(_receiver_fn_arg) => {}
+        }
+
+        acc
+    });
+}
+
+fn get_dependency_types(item_impl: &ItemImpl) -> Vec<Type>
+{
+    let impl_items = &item_impl.items;
+
+    let opt_new_method_impl_item = impl_items.iter().find(|item| match item {
+        ImplItem::Method(method_item) => method_item.sig.ident == "new",
+        &_ => false,
+    });
+
+    let new_method_impl_item = match opt_new_method_impl_item {
+        Some(item) => match item {
+            ImplItem::Method(method_item) => method_item,
+            &_ => panic!("{}", IMPL_NO_NEW_METHOD_ERR_MESSAGE),
+        },
+        None => panic!("{}", IMPL_NO_NEW_METHOD_ERR_MESSAGE),
+    };
+
+    let new_method_inputs = &new_method_impl_item.sig.inputs;
+
+    if get_fn_args_has_self(new_method_inputs) {
+        panic!("{}", IMPL_NEW_METHOD_SELF_PARAM_ERR_MESSAGE)
+    }
+
+    let new_method_arg_type_paths = get_fn_arg_type_paths(new_method_inputs);
+
+    return new_method_arg_type_paths.iter().fold(
+        Vec::<Type>::new(),
+        |mut acc, arg_type_path| {
+            let arg_type_path_string = path_to_string(&arg_type_path.path);
+
+            if arg_type_path_string != "Box"
+                && arg_type_path_string != "std::boxed::Box"
+                && arg_type_path_string != "boxed::Box"
+            {
+                panic!("{}", IMPL_NEW_METHOD_BOX_PARAMS_ERR_MESSAGE);
+            }
+
+            // Assume the type path has a last segment.
+            // The Box check wouldn't pass if it didn't
+            let last_path_segment = arg_type_path.path.segments.last().unwrap();
+
+            match &last_path_segment.arguments {
+                PathArguments::AngleBracketed(angle_bracketed_generic_args) => {
+                    let generic_args = &angle_bracketed_generic_args.args;
+
+                    let opt_first_generic_arg = generic_args.first();
+
+                    // Assume a first generic argument exists because Box requires one
+                    let first_generic_arg = opt_first_generic_arg.as_ref().unwrap();
+
+                    match first_generic_arg {
+                        GenericArgument::Type(first_generic_arg_type) => {
+                            acc.push(first_generic_arg_type.clone());
+                        }
+                        &_ => {}
+                    }
+                }
+                &_ => {}
+            }
+
+            acc
+        },
+    );
+}
+
+#[proc_macro_attribute]
+pub fn injectable(args_stream: TokenStream, impl_stream: TokenStream) -> TokenStream
+{
+    let args = parse_macro_input!(args_stream as AttributeArgs);
+
+    if args.is_empty() {
+        panic!("{}", NO_INTERFACE_ARG_ERR_MESSAGE);
+    }
+
+    if args.len() > 1 {
+        panic!("Only a single argument is expected");
+    }
+
+    let interface_path = match &args[0] {
+        NestedMeta::Meta(arg_meta) => match arg_meta {
+            Meta::Path(path_arg) => path_arg,
+            &_ => panic!("{}", INVALID_ARG_ERR_MESSAGE),
+        },
+        &_ => panic!("{}", INVALID_ARG_ERR_MESSAGE),
+    };
+
+    let item_impl: ItemImpl = match parse(impl_stream) {
+        Ok(impl_parsed) => impl_parsed,
+        Err(_) => {
+            panic!("{}", INVALID_ITEM_TYPE_ERR_MESSAGE)
+        }
+    };
+
+    let self_type = item_impl.self_ty.as_ref();
+
+    let self_type_path = match self_type {
+        Type::Path(path_self_type) => path_self_type.path.clone(),
+        &_ => parse_str("invalid_type").unwrap(),
+    };
+
+    let dependency_types = get_dependency_types(&item_impl);
+
+    quote! {
+        #item_impl
+
+        impl syrette::injectable::Injectable for #self_type_path {
+            fn resolve(
+                di_container: &syrette::DIContainer
+            ) -> error_stack::Result<Box<Self>, syrette::injectable::ResolveError>
+            {
+                use error_stack::ResultExt;
+
+                return Ok(Box::new(Self::new(
+                    #(di_container.get::<#dependency_types>()
+                        .change_context(syrette::injectable::ResolveError)
+                        .attach_printable(format!(
+                            "Unable to resolve a dependency of {}",
+                            std::any::type_name::<#self_type_path>()
+                        ))?,
+                    )*
+                )));
+            }
+        }
+
+        syrette::castable_to!(#self_type_path => #interface_path);
+    }
+    .into()
+}
+
+#[proc_macro]
+pub fn castable_to(input: TokenStream) -> TokenStream
+{
+    let Casts {
+        ty,
+        targets: Targets { flags, paths },
+    } = parse_macro_input!(input);
+
+    paths
+        .iter()
+        .map(|t| generate_caster(&ty, t, flags.contains(&Flag::Sync)))
+        .collect::<proc_macro2::TokenStream>()
+        .into()
+}
diff --git a/syrette_macros/src/libs/intertrait_macros/LICENSE-APACHE b/syrette_macros/src/libs/intertrait_macros/LICENSE-APACHE
new file mode 100644
index 0000000..d9a10c0
--- /dev/null
+++ b/syrette_macros/src/libs/intertrait_macros/LICENSE-APACHE
@@ -0,0 +1,176 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
diff --git a/syrette_macros/src/libs/intertrait_macros/LICENSE-MIT b/syrette_macros/src/libs/intertrait_macros/LICENSE-MIT
new file mode 100644
index 0000000..969d061
--- /dev/null
+++ b/syrette_macros/src/libs/intertrait_macros/LICENSE-MIT
@@ -0,0 +1,17 @@
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/syrette_macros/src/libs/intertrait_macros/args.rs b/syrette_macros/src/libs/intertrait_macros/args.rs
new file mode 100644
index 0000000..d576ae2
--- /dev/null
+++ b/syrette_macros/src/libs/intertrait_macros/args.rs
@@ -0,0 +1,99 @@
+/**
+ * Originally from Intertrait by CodeChain
+ *
+ * https://github.com/CodeChain-io/intertrait
+ * https://crates.io/crates/intertrait/0.2.2
+ *
+ * Licensed under either of
+ *
+ * Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
+
+ * at your option.
+*/
+use std::collections::HashSet;
+
+use syn::bracketed;
+use syn::parse::{Parse, ParseStream, Result};
+use syn::punctuated::Punctuated;
+use syn::{Error, Ident, Path, Token, Type};
+
+#[derive(Hash, PartialEq, Eq)]
+pub enum Flag
+{
+    Sync,
+}
+
+impl Flag
+{
+    fn from(ident: &Ident) -> Result<Self>
+    {
+        match ident.to_string().as_str() {
+            "sync" => Ok(Flag::Sync),
+            unknown => {
+                let msg = format!("Unknown flag: {}", unknown);
+                Err(Error::new_spanned(ident, msg))
+            }
+        }
+    }
+}
+
+pub struct Targets
+{
+    pub flags: HashSet<Flag>,
+    pub paths: Vec<Path>,
+}
+
+impl Parse for Targets
+{
+    fn parse(input: ParseStream) -> Result<Self>
+    {
+        let mut flags = HashSet::new();
+        let mut paths = Vec::new();
+
+        if input.is_empty() {
+            return Ok(Targets { flags, paths });
+        }
+
+        if input.peek(syn::token::Bracket) {
+            let content;
+            bracketed!(content in input);
+            for ident in Punctuated::<Ident, Token![,]>::parse_terminated(&content)? {
+                if !flags.insert(Flag::from(&ident)?) {
+                    let msg = format!("Duplicated flag: {}", ident);
+                    return Err(Error::new_spanned(ident, msg));
+                }
+            }
+        }
+
+        if input.is_empty() {
+            return Ok(Targets { flags, paths });
+        }
+
+        paths = Punctuated::<Path, Token![,]>::parse_terminated(input)?
+            .into_iter()
+            .collect();
+
+        Ok(Targets { flags, paths })
+    }
+}
+
+pub struct Casts
+{
+    pub ty: Type,
+    pub targets: Targets,
+}
+
+impl Parse for Casts
+{
+    fn parse(input: ParseStream) -> Result<Self>
+    {
+        let ty: Type = input.parse()?;
+        input.parse::<Token![=>]>()?;
+
+        Ok(Casts {
+            ty,
+            targets: input.parse()?,
+        })
+    }
+}
diff --git a/syrette_macros/src/libs/intertrait_macros/gen_caster.rs b/syrette_macros/src/libs/intertrait_macros/gen_caster.rs
new file mode 100644
index 0000000..9d177ed
--- /dev/null
+++ b/syrette_macros/src/libs/intertrait_macros/gen_caster.rs
@@ -0,0 +1,72 @@
+/**
+ * Originally from Intertrait by CodeChain
+ *
+ * https://github.com/CodeChain-io/intertrait
+ * https://crates.io/crates/intertrait/0.2.2
+ *
+ * Licensed under either of
+ *
+ * Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
+
+ * at your option.
+*/
+use std::str::from_utf8_unchecked;
+
+use proc_macro2::TokenStream;
+use uuid::adapter::Simple;
+use uuid::Uuid;
+
+use quote::format_ident;
+use quote::quote;
+use quote::ToTokens;
+
+pub fn generate_caster(
+    ty: &impl ToTokens,
+    trait_: &impl ToTokens,
+    sync: bool,
+) -> TokenStream
+{
+    let mut fn_buf = [0u8; FN_BUF_LEN];
+    let fn_ident = format_ident!("{}", new_fn_name(&mut fn_buf));
+    let new_caster = if sync {
+        quote! {
+            syrette::libs::intertrait::Caster::<dyn #trait_>::new_sync(
+                |from| from.downcast_ref::<#ty>().unwrap(),
+                |from| from.downcast_mut::<#ty>().unwrap(),
+                |from| from.downcast::<#ty>().unwrap(),
+                |from| from.downcast::<#ty>().unwrap(),
+                |from| from.downcast::<#ty>().unwrap()
+            )
+        }
+    } else {
+        quote! {
+            syrette::libs::intertrait::Caster::<dyn #trait_>::new(
+                |from| from.downcast_ref::<#ty>().unwrap(),
+                |from| from.downcast_mut::<#ty>().unwrap(),
+                |from| from.downcast::<#ty>().unwrap(),
+                |from| from.downcast::<#ty>().unwrap(),
+            )
+        }
+    };
+
+    quote! {
+        #[syrette::libs::linkme::distributed_slice(syrette::libs::intertrait::CASTERS)]
+        #[linkme(crate = syrette::libs::linkme)]
+        fn #fn_ident() -> (::std::any::TypeId, syrette::libs::intertrait::BoxedCaster) {
+            (::std::any::TypeId::of::<#ty>(), Box::new(#new_caster))
+        }
+    }
+}
+
+const FN_PREFIX: &[u8] = b"__";
+const FN_BUF_LEN: usize = FN_PREFIX.len() + Simple::LENGTH;
+
+fn new_fn_name(buf: &mut [u8]) -> &str
+{
+    buf[..FN_PREFIX.len()].copy_from_slice(FN_PREFIX);
+    Uuid::new_v4()
+        .to_simple()
+        .encode_lower(&mut buf[FN_PREFIX.len()..]);
+    unsafe { from_utf8_unchecked(&buf[..FN_BUF_LEN]) }
+}
diff --git a/syrette_macros/src/libs/intertrait_macros/mod.rs b/syrette_macros/src/libs/intertrait_macros/mod.rs
new file mode 100644
index 0000000..7904663
--- /dev/null
+++ b/syrette_macros/src/libs/intertrait_macros/mod.rs
@@ -0,0 +1,15 @@
+/**
+ * Originally from Intertrait by CodeChain
+ *
+ * https://github.com/CodeChain-io/intertrait
+ * https://crates.io/crates/intertrait/0.2.2
+ *
+ * Licensed under either of
+ *
+ * Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
+
+ * at your option.
+*/
+pub mod args;
+pub mod gen_caster;
diff --git a/syrette_macros/src/libs/mod.rs b/syrette_macros/src/libs/mod.rs
new file mode 100644
index 0000000..e4964de
--- /dev/null
+++ b/syrette_macros/src/libs/mod.rs
@@ -0,0 +1 @@
+pub mod intertrait_macros;