diff --git a/src/parser.zig b/src/parser.zig
index 9ee137c..3cd31c2 100644
--- a/src/parser.zig
+++ b/src/parser.zig
@@ -462,80 +462,7 @@ fn writeDebugFile(allocator: std.mem.Allocator, header_path: []const u8, output:
 
 fn freeDeclDeep(allocator: std.mem.Allocator, decl: patterns.Declaration) void {
     switch (decl) {
-        .opaque_type => |o| {
-            allocator.free(o.name);
-            if (o.doc_comment) |doc| allocator.free(doc);
-        },
-        .typedef_decl => |t| {
-            allocator.free(t.name);
-            allocator.free(t.underlying_type);
-            if (t.doc_comment) |doc| allocator.free(doc);
-        },
-        .function_pointer_decl => |fp| {
-            allocator.free(fp.name);
-            allocator.free(fp.return_type);
-            if (fp.doc_comment) |doc| allocator.free(doc);
-            for (fp.params) |param| {
-                allocator.free(param.name);
-                allocator.free(param.type_name);
-            }
-            allocator.free(fp.params);
-        },
-        .c_type_alias => |a| {
-            allocator.free(a.name);
-            if (a.doc_comment) |doc| allocator.free(doc);
-        },
-        .enum_decl => |e| {
-            allocator.free(e.name);
-            if (e.doc_comment) |doc| allocator.free(doc);
-            for (e.values) |val| {
-                allocator.free(val.name);
-                if (val.value) |v| allocator.free(v);
-                if (val.comment) |c| allocator.free(c);
-            }
-            allocator.free(e.values);
-        },
-        .struct_decl => |s| {
-            allocator.free(s.name);
-            if (s.doc_comment) |doc| allocator.free(doc);
-            for (s.fields) |field| {
-                allocator.free(field.name);
-                allocator.free(field.type_name);
-                if (field.comment) |c| allocator.free(c);
-            }
-            allocator.free(s.fields);
-        },
-        .union_decl => |u| {
-            allocator.free(u.name);
-            if (u.doc_comment) |doc| allocator.free(doc);
-            for (u.fields) |field| {
-                allocator.free(field.name);
-                allocator.free(field.type_name);
-                if (field.comment) |c| allocator.free(c);
-            }
-            allocator.free(u.fields);
-        },
-        .flag_decl => |f| {
-            allocator.free(f.name);
-            allocator.free(f.underlying_type);
-            if (f.doc_comment) |doc| allocator.free(doc);
-            for (f.flags) |flag| {
-                allocator.free(flag.name);
-                allocator.free(flag.value);
-                if (flag.comment) |c| allocator.free(c);
-            }
-            allocator.free(f.flags);
-        },
-        .function_decl => |func| {
-            allocator.free(func.name);
-            allocator.free(func.return_type);
-            if (func.doc_comment) |doc| allocator.free(doc);
-            for (func.params) |param| {
-                allocator.free(param.name);
-                allocator.free(param.type_name);
-            }
-            allocator.free(func.params);
-        },
+        inline else => |*d| d.deinit(allocator),
     }
 }
 
diff --git a/src/patterns.zig b/src/patterns.zig
index 51d0af9..0319c16 100644
--- a/src/patterns.zig
+++ b/src/patterns.zig
@@ -27,12 +27,28 @@ pub const Declaration = union(enum) {
 pub const OpaqueType = struct {
     name: []const u8, // SDL_GPUDevice
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: OpaqueType, allocator: Allocator) void {
+        allocator.free(self.name);
+        if (self.doc_comment) |doc| allocator.free(doc);
+    }
 };
 
 pub const EnumDecl = struct {
     name: []const u8, // SDL_GPUPrimitiveType
     values: []EnumValue,
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: EnumDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        if (self.doc_comment) |doc| allocator.free(doc);
+        for (self.values) |val| {
+            allocator.free(val.name);
+            if (val.value) |v| allocator.free(v);
+            if (val.comment) |c| allocator.free(c);
+        }
+        allocator.free(self.values);
+    }
 };
 
 pub const EnumValue = struct {
@@ -46,12 +62,34 @@ pub const StructDecl = struct {
     fields: []FieldDecl,
     doc_comment: ?[]const u8,
     has_unions: bool = false, // If true, codegen should emit as opaque (C unions can't be represented in other languages)
+
+    pub fn deinit(self: StructDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        if (self.doc_comment) |doc| allocator.free(doc);
+        for (self.fields) |field| {
+            allocator.free(field.name);
+            allocator.free(field.type_name);
+            if (field.comment) |c| allocator.free(c);
+        }
+        allocator.free(self.fields);
+    }
 };
 
 pub const UnionDecl = struct {
     name: []const u8, // SDL_Event
     fields: []FieldDecl,
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: UnionDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        if (self.doc_comment) |doc| allocator.free(doc);
+        for (self.fields) |field| {
+            allocator.free(field.name);
+            allocator.free(field.type_name);
+            if (field.comment) |c| allocator.free(c);
+        }
+        allocator.free(self.fields);
+    }
 };
 
 pub const FieldDecl = struct {
@@ -65,6 +103,18 @@ pub const FlagDecl = struct {
     underlying_type: []const u8, // Uint32
     flags: []FlagValue,
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: FlagDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        allocator.free(self.underlying_type);
+        if (self.doc_comment) |doc| allocator.free(doc);
+        for (self.flags) |flag| {
+            allocator.free(flag.name);
+            allocator.free(flag.value);
+            if (flag.comment) |c| allocator.free(c);
+        }
+        allocator.free(self.flags);
+    }
 };
 
 pub const FlagValue = struct {
@@ -77,6 +127,12 @@ pub const TypedefDecl = struct {
     name: []const u8, // SDL_PropertiesID
     underlying_type: []const u8, // Uint32
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: TypedefDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        allocator.free(self.underlying_type);
+        if (self.doc_comment) |doc| allocator.free(doc);
+    }
 };
 
 pub const FunctionPointerDecl = struct {
@@ -84,6 +140,17 @@ pub const FunctionPointerDecl = struct {
     return_type: []const u8, // Uint32
     params: []ParamDecl,
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: FunctionPointerDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        allocator.free(self.return_type);
+        if (self.doc_comment) |doc| allocator.free(doc);
+        for (self.params) |param| {
+            allocator.free(param.name);
+            allocator.free(param.type_name);
+        }
+        allocator.free(self.params);
+    }
 };
 
 /// C type alias - for function pointer typedefs that should alias to C type directly
@@ -91,6 +158,11 @@ pub const FunctionPointerDecl = struct {
 pub const CTypeAlias = struct {
     name: []const u8, // SDL_HitTest
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: CTypeAlias, allocator: Allocator) void {
+        allocator.free(self.name);
+        if (self.doc_comment) |doc| allocator.free(doc);
+    }
 };
 
 pub const FunctionDecl = struct {
@@ -98,6 +170,17 @@ pub const FunctionDecl = struct {
     return_type: []const u8, // SDL_GPUDevice *
     params: []ParamDecl,
     doc_comment: ?[]const u8,
+
+    pub fn deinit(self: FunctionDecl, allocator: Allocator) void {
+        allocator.free(self.name);
+        allocator.free(self.return_type);
+        if (self.doc_comment) |doc| allocator.free(doc);
+        for (self.params) |param| {
+            allocator.free(param.name);
+            allocator.free(param.type_name);
+        }
+        allocator.free(self.params);
+    }
 };
 
 pub const ParamDecl = struct {