1 files changed, 57 insertions, 0 deletions
diff --git a/engine/src/util.rs b/engine/src/util.rs
index b1a98ca..a7d5794 100644
--- a/engine/src/util.rs
+++ b/engine/src/util.rs
@@ -22,3 +22,60 @@ macro_rules! or {
 }
 
 pub(crate) use or;
+
+macro_rules! builder {
+    (
+        $(#[doc = $doc: literal])*
+        #[builder(
+            name = $builder_name: ident
+            $(, derives = ($($builder_derive: ident),+))?
+        )]
+        $(#[$attr: meta])*
+        $visibility: vis struct $name: ident
+        {
+            $(
+                $(#[$field_attr: meta])*
+                $field_visibility: vis $field: ident: $field_type: ty,
+            )*
+        }
+    ) => {
+        $(#[doc = $doc])*
+        $(#[$attr])*
+        $visibility struct $name
+        {
+            $(
+                $(#[$field_attr])*
+                $field_visibility $field: $field_type,
+            )*
+        }
+
+        $(#[derive($($builder_derive),+)])?
+        $visibility struct $builder_name
+        {
+            $(
+                $field: $field_type,
+            )*
+        }
+
+        impl $builder_name
+        {
+            $(
+                $visibility fn $field(mut self, $field: $field_type) -> Self
+                {
+                    self.$field = $field;
+                    self
+                }
+            )*
+
+            $visibility fn build(self) -> $name {
+                $name {
+                    $(
+                        $field: self.$field,
+                    )*
+                }
+            }
+        }
+    };
+}
+
+pub(crate) use builder;