Rust default array fix

samples/rust_generated/my_game/sample/vec_3_generated.rs

@@ -180,12 +180,21 @@ impl<'a> Vec3 {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Vec3T {
   pub x: f32,
   pub y: f32,
   pub z: f32,
 }
+impl std::default::Default for Vec3T {
+    fn default() -> Self {
+      Self {
+        x: Default::default(),
+        y: Default::default(),
+        z: Default::default(),
+    }
+  }
+}
 impl Vec3T {
   pub fn pack(&self) -> Vec3 {
     Vec3::new(

src/idl_gen_rust.cpp

@@ -2884,13 +2884,30 @@ class RustGenerator : public BaseGenerator {
     // Generate Struct Object.
     if (parser_.opts.generate_object_based_api) {
       // Struct declaration
-      code_ += "#[derive(Debug, Clone, PartialEq, Default)]";
+      code_ += "#[derive(Debug, Clone, PartialEq)]";
       code_ += "{{ACCESS_TYPE}} struct {{STRUCT_OTY}} {";
       ForAllStructFields(struct_def, [&](const FieldDef &field) {
         (void)field;  // unused.
         code_ += "pub {{FIELD}}: {{FIELD_OTY}},";
       });
       code_ += "}";
+
+      // Struct default trait implementation
+      code_ += "impl std::default::Default for {{STRUCT_OTY}} {";
+      code_ += "    fn default() -> Self {";
+      code_ += "      Self {";
+      ForAllStructFields(struct_def, [&](const FieldDef &field) {
+        const Type &type = field.value.type;
+        if (IsArray(type)) {
+          code_ += "      {{FIELD}}: [Default::default(); " + NumToString(type.fixed_length) + "],";
+        } else {
+          code_ += "      {{FIELD}}: Default::default(),";
+        }
+      });
+      code_ += "    }";
+      code_ += "  }";
+      code_ += "}";
+
       // The `pack` method that turns the native struct into its Flatbuffers
       // counterpart.
       code_ += "impl {{STRUCT_OTY}} {";

tests/arrays_test/my_game/example/array_struct_generated.rs

@@ -240,7 +240,7 @@ impl<'a> ArrayStruct {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct ArrayStructT {
   pub a: f32,
   pub b: [i32; 15],
@@ -249,6 +249,18 @@ pub struct ArrayStructT {
   pub e: i32,
   pub f: [i64; 2],
 }
+impl std::default::Default for ArrayStructT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+        b: [Default::default(); 15],
+        c: Default::default(),
+        d: [Default::default(); 2],
+        e: Default::default(),
+        f: [Default::default(); 2],
+    }
+  }
+}
 impl ArrayStructT {
   pub fn pack(&self) -> ArrayStruct {
     ArrayStruct::new(

tests/arrays_test/my_game/example/nested_struct_generated.rs

@@ -174,13 +174,23 @@ impl<'a> NestedStruct {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct NestedStructT {
   pub a: [i32; 2],
   pub b: TestEnum,
   pub c: [TestEnum; 2],
   pub d: [i64; 2],
 }
+impl std::default::Default for NestedStructT {
+    fn default() -> Self {
+      Self {
+        a: [Default::default(); 2],
+        b: Default::default(),
+        c: [Default::default(); 2],
+        d: [Default::default(); 2],
+    }
+  }
+}
 impl NestedStructT {
   pub fn pack(&self) -> NestedStruct {
     NestedStruct::new(

tests/include_test1/my_game/other_name_space/unused_generated.rs

@@ -114,10 +114,17 @@ impl<'a> Unused {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct UnusedT {
   pub a: i32,
 }
+impl std::default::Default for UnusedT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+    }
+  }
+}
 impl UnusedT {
   pub fn pack(&self) -> Unused {
     Unused::new(

tests/include_test2/my_game/other_name_space/unused_generated.rs

@@ -114,10 +114,17 @@ impl<'a> Unused {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct UnusedT {
   pub a: i32,
 }
+impl std::default::Default for UnusedT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+    }
+  }
+}
 impl UnusedT {
   pub fn pack(&self) -> Unused {
     Unused::new(

tests/monster_test/my_game/example/ability_generated.rs

@@ -157,11 +157,19 @@ impl<'a> Ability {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct AbilityT {
   pub id: u32,
   pub distance: u32,
 }
+impl std::default::Default for AbilityT {
+    fn default() -> Self {
+      Self {
+        id: Default::default(),
+        distance: Default::default(),
+    }
+  }
+}
 impl AbilityT {
   pub fn pack(&self) -> Ability {
     Ability::new(

tests/monster_test/my_game/example/struct_of_structs_generated.rs

@@ -129,12 +129,21 @@ impl<'a> StructOfStructs {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct StructOfStructsT {
   pub a: AbilityT,
   pub b: TestT,
   pub c: AbilityT,
 }
+impl std::default::Default for StructOfStructsT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+        b: Default::default(),
+        c: Default::default(),
+    }
+  }
+}
 impl StructOfStructsT {
   pub fn pack(&self) -> StructOfStructs {
     StructOfStructs::new(

tests/monster_test/my_game/example/struct_of_structs_of_structs_generated.rs

@@ -97,10 +97,17 @@ impl<'a> StructOfStructsOfStructs {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct StructOfStructsOfStructsT {
   pub a: StructOfStructsT,
 }
+impl std::default::Default for StructOfStructsOfStructsT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+    }
+  }
+}
 impl StructOfStructsOfStructsT {
   pub fn pack(&self) -> StructOfStructsOfStructs {
     StructOfStructsOfStructs::new(

tests/monster_test/my_game/example/test_generated.rs

@@ -147,11 +147,19 @@ impl<'a> Test {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct TestT {
   pub a: i16,
   pub b: i8,
 }
+impl std::default::Default for TestT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+        b: Default::default(),
+    }
+  }
+}
 impl TestT {
   pub fn pack(&self) -> Test {
     Test::new(

tests/monster_test/my_game/example/vec_3_generated.rs

@@ -262,7 +262,7 @@ impl<'a> Vec3 {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Vec3T {
   pub x: f32,
   pub y: f32,
@@ -271,6 +271,18 @@ pub struct Vec3T {
   pub test2: Color,
   pub test3: TestT,
 }
+impl std::default::Default for Vec3T {
+    fn default() -> Self {
+      Self {
+        x: Default::default(),
+        y: Default::default(),
+        z: Default::default(),
+        test1: Default::default(),
+        test2: Default::default(),
+        test3: Default::default(),
+    }
+  }
+}
 impl Vec3T {
   pub fn pack(&self) -> Vec3 {
     Vec3::new(

tests/monster_test/my_game/other_name_space/unused_generated.rs

@@ -114,10 +114,17 @@ impl<'a> Unused {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct UnusedT {
   pub a: i32,
 }
+impl std::default::Default for UnusedT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+    }
+  }
+}
 impl UnusedT {
   pub fn pack(&self) -> Unused {
     Unused::new(

tests/monster_test_serialize/my_game/example/ability_generated.rs

@@ -171,11 +171,19 @@ impl<'a> Ability {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct AbilityT {
   pub id: u32,
   pub distance: u32,
 }
+impl std::default::Default for AbilityT {
+    fn default() -> Self {
+      Self {
+        id: Default::default(),
+        distance: Default::default(),
+    }
+  }
+}
 impl AbilityT {
   pub fn pack(&self) -> Ability {
     Ability::new(

tests/monster_test_serialize/my_game/example/struct_of_structs_generated.rs

@@ -144,12 +144,21 @@ impl<'a> StructOfStructs {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct StructOfStructsT {
   pub a: AbilityT,
   pub b: TestT,
   pub c: AbilityT,
 }
+impl std::default::Default for StructOfStructsT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+        b: Default::default(),
+        c: Default::default(),
+    }
+  }
+}
 impl StructOfStructsT {
   pub fn pack(&self) -> StructOfStructs {
     StructOfStructs::new(

tests/monster_test_serialize/my_game/example/struct_of_structs_of_structs_generated.rs

@@ -110,10 +110,17 @@ impl<'a> StructOfStructsOfStructs {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct StructOfStructsOfStructsT {
   pub a: StructOfStructsT,
 }
+impl std::default::Default for StructOfStructsOfStructsT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+    }
+  }
+}
 impl StructOfStructsOfStructsT {
   pub fn pack(&self) -> StructOfStructsOfStructs {
     StructOfStructsOfStructs::new(

tests/monster_test_serialize/my_game/example/test_generated.rs

@@ -161,11 +161,19 @@ impl<'a> Test {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct TestT {
   pub a: i16,
   pub b: i8,
 }
+impl std::default::Default for TestT {
+    fn default() -> Self {
+      Self {
+        a: Default::default(),
+        b: Default::default(),
+    }
+  }
+}
 impl TestT {
   pub fn pack(&self) -> Test {
     Test::new(

tests/monster_test_serialize/my_game/example/vec_3_generated.rs

@@ -280,7 +280,7 @@ impl<'a> Vec3 {
   }
 }
 
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Vec3T {
   pub x: f32,
   pub y: f32,
@@ -289,6 +289,18 @@ pub struct Vec3T {
   pub test2: Color,
   pub test3: TestT,
 }
+impl std::default::Default for Vec3T {
+    fn default() -> Self {
+      Self {
+        x: Default::default(),
+        y: Default::default(),
+        z: Default::default(),
+        test1: Default::default(),
+        test2: Default::default(),
+        test3: Default::default(),
+    }
+  }
+}
 impl Vec3T {
   pub fn pack(&self) -> Vec3 {
     Vec3::new(