diff --git a/src/array.cpp b/src/array.cpp
index 6fe54b847..dc52eeb8d 100644
--- a/src/array.cpp
+++ b/src/array.cpp
@@ -43,11 +43,96 @@ template <typename T> void     array_set_capacity  (Array<T> *array, isize capac
 template <typename T> Array<T> array_slice         (Array<T> const &array, isize lo, isize hi);
 template <typename T> Array<T> array_clone         (gbAllocator const &a, Array<T> const &array);
 
-
-
 template <typename T> void array_ordered_remove  (Array<T> *array, isize index);
 template <typename T> void array_unordered_remove(Array<T> *array, isize index);
 
+template <typename T> void array_copy(Array<T> *array, Array<T> const &data, isize offset);
+template <typename T> void array_copy(Array<T> *array, Array<T> const &data, isize offset, isize count);
+
+template <typename T> T *array_end_ptr(Array<T> *array);
+
+
+template <typename T>
+struct Slice {
+	T *data;
+	isize count;
+
+	T &operator[](isize index) {
+		#if !defined(NO_ARRAY_BOUNDS_CHECK)
+			GB_ASSERT_MSG(0 <= index && index < count, "Index %td is out of bounds ranges 0..<%td", index, count);
+		#endif
+		return data[index];
+	}
+
+	T const &operator[](isize index) const {
+		#if !defined(NO_ARRAY_BOUNDS_CHECK)
+			GB_ASSERT_MSG(0 <= index && index < count, "Index %td is out of bounds ranges 0..<%td", index, count);
+		#endif
+		return data[index];
+	}
+};
+
+template <typename T> Slice<T> slice_from_array(Array<T> const &a);
+
+
+
+template <typename T>
+Slice<T> slice_make(gbAllocator const &allocator, isize count) {
+	Slice<T> s = {};
+	s.data = gb_alloc_array(allocator, T, count);
+	s.count = count;
+	return s;
+}
+
+
+template <typename T>
+Slice<T> slice_from_array(Array<T> const &a) {
+	return {a.data, a.count};
+}
+template <typename T>
+Slice<T> slice_clone(gbAllocator const &allocator, Slice<T> const &a) {
+	T *data = cast(T *)gb_alloc_copy_align(allocator, a.data, a.count*gb_size_of(T), gb_align_of(T));
+	return {data, a.count};
+}
+
+template <typename T>
+Slice<T> slice_clone_from_array(gbAllocator const &allocator, Array<T> const &a) {
+	auto c = array_clone(allocator, a);
+	return {c.data, c.count};
+}
+
+
+template <typename T>
+void slice_copy(Slice<T> *slice, Slice<T> const &data, isize offset) {
+	gb_memmove(slice->data+offset, data.data, gb_size_of(T)*data.count);
+}
+template <typename T>
+void slice_copy(Slice<T> *slice, Slice<T> const &data, isize offset, isize count) {
+	gb_memmove(slice->data+offset, data.data, gb_size_of(T)*gb_min(data.count, count));
+}
+
+
+
+template <typename T>
+void slice_ordered_remove(Slice<T> *array, isize index) {
+	GB_ASSERT(0 <= index && index < array->count);
+
+	isize bytes = gb_size_of(T) * (array->count-(index+1));
+	gb_memmove(array->data+index, array->data+index+1, bytes);
+	array->count -= 1;
+}
+
+template <typename T>
+void slice_unordered_remove(Slice<T> *array, isize index) {
+	GB_ASSERT(0 <= index && index < array->count);
+
+	isize n = array->count-1;
+	if (index != n) {
+		gb_memmove(array->data+index, array->data+n, gb_size_of(T));
+	}
+	array->count -= 1;
+}
+
 
 template <typename T>
 void array_copy(Array<T> *array, Array<T> const &data, isize offset) {
diff --git a/src/check_decl.cpp b/src/check_decl.cpp
index 248069b97..da07fe4bc 100644
--- a/src/check_decl.cpp
+++ b/src/check_decl.cpp
@@ -113,7 +113,7 @@ Type *check_init_variable(CheckerContext *ctx, Entity *e, Operand *operand, Stri
 	return e->type;
 }
 
-void check_init_variables(CheckerContext *ctx, Entity **lhs, isize lhs_count, Array<Ast *> const &inits, String context_name) {
+void check_init_variables(CheckerContext *ctx, Entity **lhs, isize lhs_count, Slice<Ast *> const &inits, String context_name) {
 	if ((lhs == nullptr || lhs_count == 0) && inits.count == 0) {
 		return;
 	}
diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 11ccf2dab..94a3467d2 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -73,7 +73,7 @@ void     update_expr_type               (CheckerContext *c, Ast *e, Type *type,
 bool     check_is_terminating           (Ast *node, String const &label);
 bool     check_has_break                (Ast *stmt, String const &label, bool implicit);
 void     check_stmt                     (CheckerContext *c, Ast *node, u32 flags);
-void     check_stmt_list                (CheckerContext *c, Array<Ast *> const &stmts, u32 flags);
+void     check_stmt_list                (CheckerContext *c, Slice<Ast *> const &stmts, u32 flags);
 void     check_init_constant            (CheckerContext *c, Entity *e, Operand *operand);
 bool     check_representable_as_constant(CheckerContext *c, ExactValue in_value, Type *type, ExactValue *out_value);
 bool     check_procedure_type           (CheckerContext *c, Type *type, Ast *proc_type_node, Array<Operand> *operands = nullptr);
@@ -133,7 +133,7 @@ void error_operand_no_value(Operand *o) {
 }
 
 
-void check_scope_decls(CheckerContext *c, Array<Ast *> const &nodes, isize reserve_size) {
+void check_scope_decls(CheckerContext *c, Slice<Ast *> const &nodes, isize reserve_size) {
 	Scope *s = c->scope;
 
 	check_collect_entities(c, nodes);
@@ -6062,7 +6062,7 @@ isize add_dependencies_from_unpacking(CheckerContext *c, Entity **lhs, isize lhs
 }
 
 
-bool check_assignment_arguments(CheckerContext *ctx, Array<Operand> const &lhs, Array<Operand> *operands, Array<Ast *> const &rhs) {
+bool check_assignment_arguments(CheckerContext *ctx, Array<Operand> const &lhs, Array<Operand> *operands, Slice<Ast *> const &rhs) {
 	bool optional_ok = false;
 	isize tuple_index = 0;
 	for_array(i, rhs) {
@@ -6146,7 +6146,7 @@ bool check_assignment_arguments(CheckerContext *ctx, Array<Operand> const &lhs,
 
 
 
-bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize lhs_count, Array<Operand> *operands, Array<Ast *> const &rhs, bool allow_ok, bool is_variadic) {
+bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize lhs_count, Array<Operand> *operands, Slice<Ast *> const &rhs, bool allow_ok, bool is_variadic) {
 	bool optional_ok = false;
 	isize tuple_index = 0;
 	for_array(i, rhs) {
@@ -6748,7 +6748,7 @@ Entity **populate_proc_parameter_list(CheckerContext *c, Type *proc_type, isize
 }
 
 
-bool evaluate_where_clauses(CheckerContext *ctx, Ast *call_expr, Scope *scope, Array<Ast *> *clauses, bool print_err) {
+bool evaluate_where_clauses(CheckerContext *ctx, Ast *call_expr, Scope *scope, Slice<Ast *> *clauses, bool print_err) {
 	if (clauses != nullptr) {
 		for_array(i, *clauses) {
 			Ast *clause = (*clauses)[i];
@@ -6813,7 +6813,7 @@ bool evaluate_where_clauses(CheckerContext *ctx, Ast *call_expr, Scope *scope, A
 }
 
 
-CallArgumentData check_call_arguments(CheckerContext *c, Operand *operand, Type *proc_type, Ast *call, Array<Ast *> const &args) {
+CallArgumentData check_call_arguments(CheckerContext *c, Operand *operand, Type *proc_type, Ast *call, Slice<Ast *> const &args) {
 	ast_node(ce, CallExpr, call);
 
 	CallArgumentCheckerType *call_checker = check_call_arguments_internal;
@@ -7598,7 +7598,7 @@ CallArgumentError check_polymorphic_record_type(CheckerContext *c, Operand *oper
 
 
 
-ExprKind check_call_expr(CheckerContext *c, Operand *operand, Ast *call, Ast *proc, Array<Ast *> const &args, ProcInlining inlining, Type *type_hint) {
+ExprKind check_call_expr(CheckerContext *c, Operand *operand, Ast *call, Ast *proc, Slice<Ast *> const &args, ProcInlining inlining, Type *type_hint) {
 	if (proc != nullptr &&
 	    proc->kind == Ast_BasicDirective) {
 		ast_node(bd, BasicDirective, proc);
@@ -8150,7 +8150,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 
 	case_ast_node(bl, BasicLit, node);
 		Type *t = t_invalid;
-		switch (bl->value.kind) {
+		switch (node->tav.value.kind) {
 		case ExactValue_String:     t = t_untyped_string;     break;
 		case ExactValue_Float:      t = t_untyped_float;      break;
 		case ExactValue_Complex:    t = t_untyped_complex;    break;
@@ -8168,7 +8168,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 
 		o->mode  = Addressing_Constant;
 		o->type  = t;
-		o->value = bl->value;
+		o->value = node->tav.value;
 	case_end;
 
 	case_ast_node(bd, BasicDirective, node);
@@ -9600,9 +9600,9 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 
 
 
-		auto modified_args = array_make<Ast *>(heap_allocator(), ce->args.count+1);
+		auto modified_args = slice_make<Ast *>(heap_allocator(), ce->args.count+1);
 		modified_args[0] = first_arg;
-		array_copy(&modified_args, ce->args, 1);
+		slice_copy(&modified_args, ce->args, 1);
 		ce->args = modified_args;
 		se->modified_call = true;
 
@@ -10210,7 +10210,7 @@ void check_expr_or_type(CheckerContext *c, Operand *o, Ast *e, Type *type_hint)
 
 gbString write_expr_to_string(gbString str, Ast *node);
 
-gbString write_struct_fields_to_string(gbString str, Array<Ast *> const &params) {
+gbString write_struct_fields_to_string(gbString str, Slice<Ast *> const &params) {
 	for_array(i, params) {
 		if (i > 0) {
 			str = gb_string_appendc(str, ", ");
diff --git a/src/check_stmt.cpp b/src/check_stmt.cpp
index 4cafa8df5..ad72256c3 100644
--- a/src/check_stmt.cpp
+++ b/src/check_stmt.cpp
@@ -15,7 +15,7 @@ bool is_divigering_stmt(Ast *stmt) {
 	return t->kind == Type_Proc && t->Proc.diverging;
 }
 
-void check_stmt_list(CheckerContext *ctx, Array<Ast *> const &stmts, u32 flags) {
+void check_stmt_list(CheckerContext *ctx, Slice<Ast *> const &stmts, u32 flags) {
 	if (stmts.count == 0) {
 		return;
 	}
@@ -78,7 +78,7 @@ void check_stmt_list(CheckerContext *ctx, Array<Ast *> const &stmts, u32 flags)
 	}
 }
 
-bool check_is_terminating_list(Array<Ast *> const &stmts, String const &label) {
+bool check_is_terminating_list(Slice<Ast *> const &stmts, String const &label) {
 	// Iterate backwards
 	for (isize n = stmts.count-1; n >= 0; n--) {
 		Ast *stmt = stmts[n];
@@ -96,7 +96,7 @@ bool check_is_terminating_list(Array<Ast *> const &stmts, String const &label) {
 	return false;
 }
 
-bool check_has_break_list(Array<Ast *> const &stmts, String const &label, bool implicit) {
+bool check_has_break_list(Slice<Ast *> const &stmts, String const &label, bool implicit) {
 	for_array(i, stmts) {
 		Ast *stmt = stmts[i];
 		if (check_has_break(stmt, label, implicit)) {
diff --git a/src/check_type.cpp b/src/check_type.cpp
index af0c70119..6ea17eca6 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -117,7 +117,7 @@ bool does_field_type_allow_using(Type *t) {
 	return false;
 }
 
-void check_struct_fields(CheckerContext *ctx, Ast *node, Array<Entity *> *fields, Array<String> *tags, Array<Ast *> const &params,
+void check_struct_fields(CheckerContext *ctx, Ast *node, Array<Entity *> *fields, Array<String> *tags, Slice<Ast *> const &params,
                          isize init_field_capacity, Type *struct_type, String context) {
 	*fields = array_make<Entity *>(heap_allocator(), 0, init_field_capacity);
 	*tags   = array_make<String>(heap_allocator(), 0, init_field_capacity);
@@ -389,7 +389,7 @@ void check_struct_type(CheckerContext *ctx, Type *struct_type, Ast *node, Array<
 
 	if (st->polymorphic_params != nullptr) {
 		ast_node(field_list, FieldList, st->polymorphic_params);
-		Array<Ast *> params = field_list->list;
+		Slice<Ast *> params = field_list->list;
 		if (params.count != 0) {
 			isize variable_count = 0;
 			for_array(i, params) {
@@ -607,7 +607,7 @@ void check_union_type(CheckerContext *ctx, Type *union_type, Ast *node, Array<Op
 
 	if (ut->polymorphic_params != nullptr) {
 		ast_node(field_list, FieldList, ut->polymorphic_params);
-		Array<Ast *> params = field_list->list;
+		Slice<Ast *> params = field_list->list;
 		if (params.count != 0) {
 			isize variable_count = 0;
 			for_array(i, params) {
@@ -1516,7 +1516,7 @@ Type *check_get_params(CheckerContext *ctx, Scope *scope, Ast *_params, bool *is
 
 	bool success = true;
 	ast_node(field_list, FieldList, _params);
-	Array<Ast *> params = field_list->list;
+	Slice<Ast *> params = field_list->list;
 
 	if (params.count == 0) {
 		if (success_) *success_ = success;
@@ -1875,7 +1875,7 @@ Type *check_get_results(CheckerContext *ctx, Scope *scope, Ast *_results) {
 		return nullptr;
 	}
 	ast_node(field_list, FieldList, _results);
-	Array<Ast *> results = field_list->list;
+	Slice<Ast *> results = field_list->list;
 
 	if (results.count == 0) {
 		return nullptr;
diff --git a/src/checker.cpp b/src/checker.cpp
index 380872f24..f02b927c3 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -2854,7 +2854,7 @@ void check_decl_attributes(CheckerContext *c, Array<Ast *> const &attributes, De
 }
 
 
-isize get_total_value_count(Array<Ast *> const &values) {
+isize get_total_value_count(Slice<Ast *> const &values) {
 	isize count = 0;
 	for_array(i, values) {
 		Type *t = type_of_expr(values[i]);
@@ -3068,7 +3068,7 @@ void check_collect_value_decl(CheckerContext *c, Ast *decl) {
 				} else {
 					entity_visibility_kind = kind;
 				}
-				array_unordered_remove(elems, j);
+				slice_unordered_remove(elems, j);
 				j -= 1;
 			}
 		}
@@ -3252,7 +3252,7 @@ void check_add_foreign_block_decl(CheckerContext *ctx, Ast *decl) {
 }
 
 // NOTE(bill): If file_scopes == nullptr, this will act like a local scope
-void check_collect_entities(CheckerContext *c, Array<Ast *> const &nodes) {
+void check_collect_entities(CheckerContext *c, Slice<Ast *> const &nodes) {
 	for_array(decl_index, nodes) {
 		Ast *decl = nodes[decl_index];
 		if (!is_ast_decl(decl) && !is_ast_when_stmt(decl)) {
@@ -3783,7 +3783,7 @@ void check_add_foreign_import_decl(CheckerContext *ctx, Ast *decl) {
 	}
 }
 
-bool collect_checked_packages_from_decl_list(Checker *c, Array<Ast *> const &decls) {
+bool collect_checked_packages_from_decl_list(Checker *c, Slice<Ast *> const &decls) {
 	bool new_files = false;
 	for_array(i, decls) {
 		Ast *decl = decls[i];
@@ -3805,7 +3805,7 @@ bool collect_checked_packages_from_decl_list(Checker *c, Array<Ast *> const &dec
 }
 
 // Returns true if a new package is present
-bool collect_file_decls(CheckerContext *ctx, Array<Ast *> const &decls);
+bool collect_file_decls(CheckerContext *ctx, Slice<Ast *> const &decls);
 bool collect_file_decls_from_when_stmt(CheckerContext *ctx, AstWhenStmt *ws);
 
 bool collect_when_stmt_from_file(CheckerContext *ctx, AstWhenStmt *ws) {
@@ -3880,7 +3880,7 @@ bool collect_file_decls_from_when_stmt(CheckerContext *ctx, AstWhenStmt *ws) {
 	return false;
 }
 
-bool collect_file_decls(CheckerContext *ctx, Array<Ast *> const &decls) {
+bool collect_file_decls(CheckerContext *ctx, Slice<Ast *> const &decls) {
 	GB_ASSERT(ctx->scope->flags&ScopeFlag_File);
 
 	if (collect_checked_packages_from_decl_list(ctx->checker, decls)) {
diff --git a/src/checker.hpp b/src/checker.hpp
index e6111d2af..9c9b77ac3 100644
--- a/src/checker.hpp
+++ b/src/checker.hpp
@@ -384,7 +384,7 @@ void check_add_foreign_import_decl(CheckerContext *c, Ast *decl);
 
 
 bool check_arity_match(CheckerContext *c, AstValueDecl *vd, bool is_global = false);
-void check_collect_entities(CheckerContext *c, Array<Ast *> const &nodes);
+void check_collect_entities(CheckerContext *c, Slice<Ast *> const &nodes);
 void check_collect_entities_from_when_stmt(CheckerContext *c, AstWhenStmt *ws);
 void check_delayed_file_import_entity(CheckerContext *c, Ast *decl);
 
diff --git a/src/entity.cpp b/src/entity.cpp
index 708b0862c..0aece39c3 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -165,7 +165,7 @@ struct Entity {
 			Scope *scope;
 		} ImportName;
 		struct {
-			Array<String> paths;
+			Slice<String> paths;
 			String name;
 		} LibraryName;
 		i32 Nil;
@@ -333,7 +333,7 @@ Entity *alloc_entity_import_name(Scope *scope, Token token, Type *type,
 }
 
 Entity *alloc_entity_library_name(Scope *scope, Token token, Type *type,
-                                  Array<String> paths, String name) {
+                                  Slice<String> paths, String name) {
 	Entity *entity = alloc_entity(Entity_LibraryName, scope, token, type);
 	entity->LibraryName.paths = paths;
 	entity->LibraryName.name = name;
diff --git a/src/ir.cpp b/src/ir.cpp
index 7b6301e30..1f2819ccf 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -6884,7 +6884,7 @@ irValue *ir_find_global_variable(irProcedure *proc, String name) {
 	return *value;
 }
 
-void ir_build_stmt_list(irProcedure *proc, Array<Ast *> stmts);
+void ir_build_stmt_list(irProcedure *proc, Slice<Ast *> stmts);
 void ir_build_assign_op(irProcedure *proc, irAddr const &lhs, irValue *value, TokenKind op);
 
 bool is_double_pointer(Type *t) {
@@ -9689,7 +9689,7 @@ void ir_build_constant_value_decl(irProcedure *proc, AstValueDecl *vd) {
 	}
 }
 
-void ir_build_stmt_list(irProcedure *proc, Array<Ast *> stmts) {
+void ir_build_stmt_list(irProcedure *proc, Slice<Ast *> stmts) {
 	// NOTE(bill): Precollect constant entities
 	for_array(i, stmts) {
 		Ast *stmt = stmts[i];
@@ -10899,7 +10899,7 @@ void ir_build_stmt_internal(irProcedure *proc, Ast *node) {
 
 		ast_node(body, BlockStmt, ss->body);
 
-		Array<Ast *> default_stmts = {};
+		Slice<Ast *> default_stmts = {};
 		irBlock *default_fall = nullptr;
 		irBlock *default_block = nullptr;
 
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 6542da69b..50d200551 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -3134,7 +3134,7 @@ void lb_build_constant_value_decl(lbProcedure *p, AstValueDecl *vd) {
 }
 
 
-void lb_build_stmt_list(lbProcedure *p, Array<Ast *> const &stmts) {
+void lb_build_stmt_list(lbProcedure *p, Slice<Ast *> const &stmts) {
 	for_array(i, stmts) {
 		Ast *stmt = stmts[i];
 		switch (stmt->kind) {
@@ -3865,7 +3865,7 @@ void lb_build_switch_stmt(lbProcedure *p, AstSwitchStmt *ss) {
 
 	ast_node(body, BlockStmt, ss->body);
 
-	Array<Ast *> default_stmts = {};
+	Slice<Ast *> default_stmts = {};
 	lbBlock *default_fall = nullptr;
 	lbBlock *default_block = nullptr;
 
diff --git a/src/parser.cpp b/src/parser.cpp
index 476504d52..cf464f149 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -126,7 +126,7 @@ Ast *alloc_ast_node(AstFile *f, AstKind kind) {
 }
 
 Ast *clone_ast(Ast *node);
-Array<Ast *> clone_ast_array(Array<Ast *> array) {
+Array<Ast *> clone_ast_array(Array<Ast *> const &array) {
 	Array<Ast *> result = {};
 	if (array.count > 0) {
 		result = array_make<Ast *>(ast_allocator(nullptr), array.count);
@@ -136,6 +136,16 @@ Array<Ast *> clone_ast_array(Array<Ast *> array) {
 	}
 	return result;
 }
+Slice<Ast *> clone_ast_array(Slice<Ast *> const &array) {
+	Slice<Ast *> result = {};
+	if (array.count > 0) {
+		result = slice_clone(permanent_allocator(), array);
+		for_array(i, array) {
+			result[i] = clone_ast(array[i]);
+		}
+	}
+	return result;
+}
 
 Ast *clone_ast(Ast *node) {
 	if (node == nullptr) {
@@ -537,10 +547,10 @@ Ast *ast_paren_expr(AstFile *f, Ast *expr, Token open, Token close) {
 	return result;
 }
 
-Ast *ast_call_expr(AstFile *f, Ast *proc, Array<Ast *> args, Token open, Token close, Token ellipsis) {
+Ast *ast_call_expr(AstFile *f, Ast *proc, Array<Ast *> const &args, Token open, Token close, Token ellipsis) {
 	Ast *result = alloc_ast_node(f, Ast_CallExpr);
 	result->CallExpr.proc     = proc;
-	result->CallExpr.args     = args;
+	result->CallExpr.args     = slice_from_array(args);
 	result->CallExpr.open     = open;
 	result->CallExpr.close    = close;
 	result->CallExpr.ellipsis = ellipsis;
@@ -624,7 +634,8 @@ Ast *ast_undef(AstFile *f, Token token) {
 Ast *ast_basic_lit(AstFile *f, Token basic_lit) {
 	Ast *result = alloc_ast_node(f, Ast_BasicLit);
 	result->BasicLit.token = basic_lit;
-	result->BasicLit.value = exact_value_from_basic_literal(basic_lit);
+	result->tav.mode = Addressing_Constant;
+	result->tav.value = exact_value_from_basic_literal(basic_lit);
 	return result;
 }
 
@@ -643,12 +654,12 @@ Ast *ast_ellipsis(AstFile *f, Token token, Ast *expr) {
 }
 
 
-Ast *ast_proc_group(AstFile *f, Token token, Token open, Token close, Array<Ast *> args) {
+Ast *ast_proc_group(AstFile *f, Token token, Token open, Token close, Array<Ast *> const &args) {
 	Ast *result = alloc_ast_node(f, Ast_ProcGroup);
 	result->ProcGroup.token = token;
 	result->ProcGroup.open  = open;
 	result->ProcGroup.close = close;
-	result->ProcGroup.args = args;
+	result->ProcGroup.args = slice_from_array(args);
 	return result;
 }
 
@@ -658,7 +669,7 @@ Ast *ast_proc_lit(AstFile *f, Ast *type, Ast *body, u64 tags, Token where_token,
 	result->ProcLit.body = body;
 	result->ProcLit.tags = tags;
 	result->ProcLit.where_token = where_token;
-	result->ProcLit.where_clauses = where_clauses;
+	result->ProcLit.where_clauses = slice_from_array(where_clauses);
 	return result;
 }
 
@@ -670,10 +681,10 @@ Ast *ast_field_value(AstFile *f, Ast *field, Ast *value, Token eq) {
 	return result;
 }
 
-Ast *ast_compound_lit(AstFile *f, Ast *type, Array<Ast *> elems, Token open, Token close) {
+Ast *ast_compound_lit(AstFile *f, Ast *type, Array<Ast *> const &elems, Token open, Token close) {
 	Ast *result = alloc_ast_node(f, Ast_CompoundLit);
 	result->CompoundLit.type = type;
-	result->CompoundLit.elems = elems;
+	result->CompoundLit.elems = slice_from_array(elems);
 	result->CompoundLit.open = open;
 	result->CompoundLit.close = close;
 	return result;
@@ -736,7 +747,7 @@ Ast *ast_inline_asm_expr(AstFile *f, Token token, Token open, Token close,
 	result->InlineAsmExpr.token              = token;
 	result->InlineAsmExpr.open               = open;
 	result->InlineAsmExpr.close              = close;
-	result->InlineAsmExpr.param_types        = param_types;
+	result->InlineAsmExpr.param_types        = slice_from_array(param_types);
 	result->InlineAsmExpr.return_type        = return_type;
 	result->InlineAsmExpr.asm_string         = asm_string;
 	result->InlineAsmExpr.constraints_string = constraints_string;
@@ -768,18 +779,18 @@ Ast *ast_expr_stmt(AstFile *f, Ast *expr) {
 	return result;
 }
 
-Ast *ast_assign_stmt(AstFile *f, Token op, Array<Ast *> lhs, Array<Ast *> rhs) {
+Ast *ast_assign_stmt(AstFile *f, Token op, Array<Ast *> const &lhs, Array<Ast *> const &rhs) {
 	Ast *result = alloc_ast_node(f, Ast_AssignStmt);
 	result->AssignStmt.op = op;
-	result->AssignStmt.lhs = lhs;
-	result->AssignStmt.rhs = rhs;
+	result->AssignStmt.lhs = slice_from_array(lhs);
+	result->AssignStmt.rhs = slice_from_array(rhs);
 	return result;
 }
 
 
-Ast *ast_block_stmt(AstFile *f, Array<Ast *> stmts, Token open, Token close) {
+Ast *ast_block_stmt(AstFile *f, Array<Ast *> const &stmts, Token open, Token close) {
 	Ast *result = alloc_ast_node(f, Ast_BlockStmt);
-	result->BlockStmt.stmts = stmts;
+	result->BlockStmt.stmts = slice_from_array(stmts);
 	result->BlockStmt.open = open;
 	result->BlockStmt.close = close;
 	return result;
@@ -805,10 +816,10 @@ Ast *ast_when_stmt(AstFile *f, Token token, Ast *cond, Ast *body, Ast *else_stmt
 }
 
 
-Ast *ast_return_stmt(AstFile *f, Token token, Array<Ast *> results) {
+Ast *ast_return_stmt(AstFile *f, Token token, Array<Ast *> const &results) {
 	Ast *result = alloc_ast_node(f, Ast_ReturnStmt);
 	result->ReturnStmt.token = token;
-	result->ReturnStmt.results = results;
+	result->ReturnStmt.results = slice_from_array(results);
 	return result;
 }
 
@@ -866,11 +877,11 @@ Ast *ast_type_switch_stmt(AstFile *f, Token token, Ast *tag, Ast *body) {
 	return result;
 }
 
-Ast *ast_case_clause(AstFile *f, Token token, Array<Ast *> list, Array<Ast *> stmts) {
+Ast *ast_case_clause(AstFile *f, Token token, Array<Ast *> const &list, Array<Ast *> const &stmts) {
 	Ast *result = alloc_ast_node(f, Ast_CaseClause);
 	result->CaseClause.token = token;
-	result->CaseClause.list  = list;
-	result->CaseClause.stmts = stmts;
+	result->CaseClause.list  = slice_from_array(list);
+	result->CaseClause.stmts = slice_from_array(stmts);
 	return result;
 }
 
@@ -889,10 +900,10 @@ Ast *ast_branch_stmt(AstFile *f, Token token, Ast *label) {
 	return result;
 }
 
-Ast *ast_using_stmt(AstFile *f, Token token, Array<Ast *> list) {
+Ast *ast_using_stmt(AstFile *f, Token token, Array<Ast *> const &list) {
 	Ast *result = alloc_ast_node(f, Ast_UsingStmt);
 	result->UsingStmt.token = token;
-	result->UsingStmt.list  = list;
+	result->UsingStmt.list  = slice_from_array(list);
 	return result;
 }
 
@@ -905,10 +916,10 @@ Ast *ast_bad_decl(AstFile *f, Token begin, Token end) {
 	return result;
 }
 
-Ast *ast_field(AstFile *f, Array<Ast *> names, Ast *type, Ast *default_value, u32 flags, Token tag,
+Ast *ast_field(AstFile *f, Array<Ast *> const &names, Ast *type, Ast *default_value, u32 flags, Token tag,
                CommentGroup *docs, CommentGroup *comment) {
 	Ast *result = alloc_ast_node(f, Ast_Field);
-	result->Field.names         = names;
+	result->Field.names         = slice_from_array(names);
 	result->Field.type          = type;
 	result->Field.default_value = default_value;
 	result->Field.flags         = flags;
@@ -918,10 +929,10 @@ Ast *ast_field(AstFile *f, Array<Ast *> names, Ast *type, Ast *default_value, u3
 	return result;
 }
 
-Ast *ast_field_list(AstFile *f, Token token, Array<Ast *> list) {
+Ast *ast_field_list(AstFile *f, Token token, Array<Ast *> const &list) {
 	Ast *result = alloc_ast_node(f, Ast_FieldList);
 	result->FieldList.token = token;
-	result->FieldList.list  = list;
+	result->FieldList.list  = slice_from_array(list);
 	return result;
 }
 
@@ -1002,7 +1013,7 @@ Ast *ast_dynamic_array_type(AstFile *f, Token token, Ast *elem) {
 	return result;
 }
 
-Ast *ast_struct_type(AstFile *f, Token token, Array<Ast *> fields, isize field_count,
+Ast *ast_struct_type(AstFile *f, Token token, Slice<Ast *> fields, isize field_count,
                      Ast *polymorphic_params, bool is_packed, bool is_raw_union,
                      Ast *align,
                      Token where_token, Array<Ast *> const &where_clauses) {
@@ -1015,38 +1026,38 @@ Ast *ast_struct_type(AstFile *f, Token token, Array<Ast *> fields, isize field_c
 	result->StructType.is_raw_union       = is_raw_union;
 	result->StructType.align              = align;
 	result->StructType.where_token        = where_token;
-	result->StructType.where_clauses      = where_clauses;
+	result->StructType.where_clauses      = slice_from_array(where_clauses);
 	return result;
 }
 
 
-Ast *ast_union_type(AstFile *f, Token token, Array<Ast *> variants, Ast *polymorphic_params, Ast *align, bool no_nil, bool maybe,
+Ast *ast_union_type(AstFile *f, Token token, Array<Ast *> const &variants, Ast *polymorphic_params, Ast *align, bool no_nil, bool maybe,
                     Token where_token, Array<Ast *> const &where_clauses) {
 	Ast *result = alloc_ast_node(f, Ast_UnionType);
 	result->UnionType.token              = token;
-	result->UnionType.variants           = variants;
+	result->UnionType.variants           = slice_from_array(variants);
 	result->UnionType.polymorphic_params = polymorphic_params;
 	result->UnionType.align              = align;
 	result->UnionType.no_nil             = no_nil;
-	result->UnionType.maybe             = maybe;
+	result->UnionType.maybe              = maybe;
 	result->UnionType.where_token        = where_token;
-	result->UnionType.where_clauses      = where_clauses;
+	result->UnionType.where_clauses      = slice_from_array(where_clauses);
 	return result;
 }
 
 
-Ast *ast_enum_type(AstFile *f, Token token, Ast *base_type, Array<Ast *> fields) {
+Ast *ast_enum_type(AstFile *f, Token token, Ast *base_type, Array<Ast *> const &fields) {
 	Ast *result = alloc_ast_node(f, Ast_EnumType);
 	result->EnumType.token = token;
 	result->EnumType.base_type = base_type;
-	result->EnumType.fields = fields;
+	result->EnumType.fields = slice_from_array(fields);
 	return result;
 }
 
-Ast *ast_bit_field_type(AstFile *f, Token token, Array<Ast *> fields, Ast *align) {
+Ast *ast_bit_field_type(AstFile *f, Token token, Array<Ast *> const &fields, Ast *align) {
 	Ast *result = alloc_ast_node(f, Ast_BitFieldType);
 	result->BitFieldType.token = token;
-	result->BitFieldType.fields = fields;
+	result->BitFieldType.fields = slice_from_array(fields);
 	result->BitFieldType.align = align;
 	return result;
 }
@@ -1069,7 +1080,7 @@ Ast *ast_map_type(AstFile *f, Token token, Ast *key, Ast *value) {
 
 
 Ast *ast_foreign_block_decl(AstFile *f, Token token, Ast *foreign_library, Ast *body,
-                                CommentGroup *docs) {
+                            CommentGroup *docs) {
 	Ast *result = alloc_ast_node(f, Ast_ForeignBlockDecl);
 	result->ForeignBlockDecl.token           = token;
 	result->ForeignBlockDecl.foreign_library = foreign_library;
@@ -1087,12 +1098,12 @@ Ast *ast_label_decl(AstFile *f, Token token, Ast *name) {
 	return result;
 }
 
-Ast *ast_value_decl(AstFile *f, Array<Ast *> names, Ast *type, Array<Ast *> values, bool is_mutable,
+Ast *ast_value_decl(AstFile *f, Array<Ast *> const &names, Ast *type, Array<Ast *> const &values, bool is_mutable,
                         CommentGroup *docs, CommentGroup *comment) {
 	Ast *result = alloc_ast_node(f, Ast_ValueDecl);
-	result->ValueDecl.names      = names;
+	result->ValueDecl.names      = slice_from_array(names);
 	result->ValueDecl.type       = type;
-	result->ValueDecl.values     = values;
+	result->ValueDecl.values     = slice_from_array(values);
 	result->ValueDecl.is_mutable = is_mutable;
 	result->ValueDecl.docs       = docs;
 	result->ValueDecl.comment    = comment;
@@ -1126,7 +1137,7 @@ Ast *ast_foreign_import_decl(AstFile *f, Token token, Array<Token> filepaths, To
                                  CommentGroup *docs, CommentGroup *comment) {
 	Ast *result = alloc_ast_node(f, Ast_ForeignImportDecl);
 	result->ForeignImportDecl.token        = token;
-	result->ForeignImportDecl.filepaths    = filepaths;
+	result->ForeignImportDecl.filepaths    = slice_from_array(filepaths);
 	result->ForeignImportDecl.library_name = library_name;
 	result->ForeignImportDecl.docs         = docs;
 	result->ForeignImportDecl.comment      = comment;
@@ -1136,11 +1147,11 @@ Ast *ast_foreign_import_decl(AstFile *f, Token token, Array<Token> filepaths, To
 }
 
 
-Ast *ast_attribute(AstFile *f, Token token, Token open, Token close, Array<Ast *> elems) {
+Ast *ast_attribute(AstFile *f, Token token, Token open, Token close, Array<Ast *> const &elems) {
 	Ast *result = alloc_ast_node(f, Ast_Attribute);
 	result->Attribute.token = token;
 	result->Attribute.open  = open;
-	result->Attribute.elems = elems;
+	result->Attribute.elems = slice_from_array(elems);
 	result->Attribute.close = close;
 	return result;
 }
@@ -1192,7 +1203,7 @@ CommentGroup *consume_comment_group(AstFile *f, isize n, isize *end_line_) {
 	CommentGroup *comments = nullptr;
 	if (list.count > 0) {
 		comments = gb_alloc_item(heap_allocator(), CommentGroup);
-		comments->list = list;
+		comments->list = slice_from_array(list);
 		array_add(&f->comments, comments);
 	}
 	return comments;
@@ -2181,7 +2192,7 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 		Ast *fields = parse_struct_field_list(f, &name_count);
 		Token    close  = expect_token(f, Token_CloseBrace);
 
-		Array<Ast *> decls = {};
+		Slice<Ast *> decls = {};
 		if (fields != nullptr) {
 			GB_ASSERT(fields->kind == Ast_FieldList);
 			decls = fields->FieldList.list;
@@ -4887,7 +4898,7 @@ bool determine_path_from_string(gbMutex *file_mutex, Ast *node, String base_dir,
 
 
 
-void parse_setup_file_decls(Parser *p, AstFile *f, String base_dir, Array<Ast *> &decls);
+void parse_setup_file_decls(Parser *p, AstFile *f, String base_dir, Slice<Ast *> &decls);
 
 void parse_setup_file_when_stmt(Parser *p, AstFile *f, String base_dir, AstWhenStmt *ws) {
 	if (ws->body != nullptr) {
@@ -4908,7 +4919,7 @@ void parse_setup_file_when_stmt(Parser *p, AstFile *f, String base_dir, AstWhenS
 	}
 }
 
-void parse_setup_file_decls(Parser *p, AstFile *f, String base_dir, Array<Ast *> &decls) {
+void parse_setup_file_decls(Parser *p, AstFile *f, String base_dir, Slice<Ast *> &decls) {
 	for_array(i, decls) {
 		Ast *node = decls[i];
 		if (!is_ast_decl(node) &&
@@ -4947,8 +4958,7 @@ void parse_setup_file_decls(Parser *p, AstFile *f, String base_dir, Array<Ast *>
 		} else if (node->kind == Ast_ForeignImportDecl) {
 			ast_node(fl, ForeignImportDecl, node);
 
-			fl->fullpaths.allocator = heap_allocator();
-			array_reserve(&fl->fullpaths, fl->filepaths.count);
+			auto fullpaths = array_make<String>(permanent_allocator(), 0, fl->filepaths.count);
 
 			for_array(fp_idx, fl->filepaths) {
 				String file_str = fl->filepaths[fp_idx].string;
@@ -4962,14 +4972,17 @@ void parse_setup_file_decls(Parser *p, AstFile *f, String base_dir, Array<Ast *>
 					}
 					fullpath = foreign_path;
 				}
-				array_add(&fl->fullpaths, fullpath);
+				array_add(&fullpaths, fullpath);
 			}
-			if (fl->fullpaths.count == 0) {
+			if (fullpaths.count == 0) {
 				syntax_error(decls[i], "No foreign paths found");
 				decls[i] = ast_bad_decl(f, fl->filepaths[0], fl->filepaths[fl->filepaths.count-1]);
 				goto end;
 			}
 
+			fl->fullpaths = slice_from_array(fullpaths);
+
+
 		} else if (node->kind == Ast_WhenStmt) {
 			ast_node(ws, WhenStmt, node);
 			parse_setup_file_when_stmt(p, f, base_dir, ws);
@@ -5131,12 +5144,12 @@ bool parse_file(Parser *p, AstFile *f) {
 	f->pkg_decl = pd;
 
 	if (f->error_count == 0) {
-		f->decls = array_make<Ast *>(heap_allocator());
+		auto decls = array_make<Ast *>(heap_allocator());
 
 		while (f->curr_token.kind != Token_EOF) {
 			Ast *stmt = parse_stmt(f);
 			if (stmt && stmt->kind != Ast_EmptyStmt) {
-				array_add(&f->decls, stmt);
+				array_add(&decls, stmt);
 				if (stmt->kind == Ast_ExprStmt &&
 				    stmt->ExprStmt.expr != nullptr &&
 				    stmt->ExprStmt.expr->kind == Ast_ProcLit) {
@@ -5145,6 +5158,8 @@ bool parse_file(Parser *p, AstFile *f) {
 			}
 		}
 
+		f->decls = slice_from_array(decls);
+
 		parse_setup_file_decls(p, f, base_dir, f->decls);
 	}
 
diff --git a/src/parser.hpp b/src/parser.hpp
index 9a7ddd4b9..3be7939fa 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -46,7 +46,7 @@ enum ParseFileError {
 };
 
 struct CommentGroup {
-	Array<Token> list; // Token_Comment
+	Slice<Token> list; // Token_Comment
 };
 
 
@@ -98,8 +98,8 @@ struct AstFile {
 	bool         in_foreign_block;
 	bool         allow_type;
 
-	Array<Ast *> decls;
-	Array<Ast *> imports; // 'import' 'using import'
+	Slice<Ast *> decls;
+	Array<Ast *> imports; // 'import'
 	isize        directive_count;
 
 	Ast *        curr_proc;
@@ -277,7 +277,6 @@ char const *inline_asm_dialect_strings[InlineAsmDialect_COUNT] = {
 	AST_KIND(Undef,          "undef",           Token) \
 	AST_KIND(BasicLit,       "basic literal",   struct { \
 		Token token; \
-		ExactValue value; \
 	}) \
 	AST_KIND(BasicDirective, "basic directive", struct { \
 		Token  token; \
@@ -291,7 +290,7 @@ char const *inline_asm_dialect_strings[InlineAsmDialect_COUNT] = {
 		Token        token; \
 		Token        open;  \
 		Token        close; \
-		Array<Ast *> args;  \
+		Slice<Ast *> args;  \
 	}) \
 	AST_KIND(ProcLit, "procedure literal", struct { \
 		Ast *type; \
@@ -299,12 +298,12 @@ char const *inline_asm_dialect_strings[InlineAsmDialect_COUNT] = {
 		u64  tags; \
 		ProcInlining inlining; \
 		Token where_token; \
-		Array<Ast *> where_clauses; \
+		Slice<Ast *> where_clauses; \
 		DeclInfo *decl; \
 	}) \
 	AST_KIND(CompoundLit, "compound literal", struct { \
 		Ast *type; \
-		Array<Ast *> elems; \
+		Slice<Ast *> elems; \
 		Token open, close; \
 		i64 max_count; \
 	}) \
@@ -327,7 +326,7 @@ AST_KIND(_ExprBegin,  "",  bool) \
 	}) \
 	AST_KIND(CallExpr,     "call expression", struct { \
 		Ast *        proc; \
-		Array<Ast *> args; \
+		Slice<Ast *> args; \
 		Token        open; \
 		Token        close; \
 		Token        ellipsis; \
@@ -344,7 +343,7 @@ AST_KIND(_ExprBegin,  "",  bool) \
 	AST_KIND(InlineAsmExpr, "inline asm expression", struct { \
 		Token token; \
 		Token open, close; \
-		Array<Ast *> param_types; \
+		Slice<Ast *> param_types; \
 		Ast *return_type; \
 		Ast *asm_string; \
 		Ast *constraints_string; \
@@ -364,11 +363,11 @@ AST_KIND(_StmtBegin,     "", bool) \
 	}) \
 	AST_KIND(AssignStmt, "assign statement", struct { \
 		Token op; \
-		Array<Ast *> lhs, rhs; \
+		Slice<Ast *> lhs, rhs; \
 	}) \
 AST_KIND(_ComplexStmtBegin, "", bool) \
 	AST_KIND(BlockStmt, "block statement", struct { \
-		Array<Ast *> stmts; \
+		Slice<Ast *> stmts; \
 		Ast *label;         \
 		Token open, close; \
 	}) \
@@ -390,7 +389,7 @@ AST_KIND(_ComplexStmtBegin, "", bool) \
 	}) \
 	AST_KIND(ReturnStmt, "return statement", struct { \
 		Token token; \
-		Array<Ast *> results; \
+		Slice<Ast *> results; \
 	}) \
 	AST_KIND(ForStmt, "for statement", struct { \
 		Token token; \
@@ -420,8 +419,8 @@ AST_KIND(_ComplexStmtBegin, "", bool) \
 	}) \
 	AST_KIND(CaseClause, "case clause", struct { \
 		Token token;             \
-		Array<Ast *> list;   \
-		Array<Ast *> stmts;  \
+		Slice<Ast *> list;   \
+		Slice<Ast *> stmts;  \
 		Entity *implicit_entity; \
 	}) \
 	AST_KIND(SwitchStmt, "switch statement", struct { \
@@ -438,12 +437,12 @@ AST_KIND(_ComplexStmtBegin, "", bool) \
 		Ast *tag;    \
 		Ast *body;   \
 		bool partial; \
-}) \
+	}) \
 	AST_KIND(DeferStmt,  "defer statement",  struct { Token token; Ast *stmt; }) \
 	AST_KIND(BranchStmt, "branch statement", struct { Token token; Ast *label; }) \
 	AST_KIND(UsingStmt,  "using statement",  struct { \
 		Token token; \
-		Array<Ast *> list; \
+		Slice<Ast *> list; \
 	}) \
 AST_KIND(_ComplexStmtEnd, "", bool) \
 AST_KIND(_StmtEnd,        "", bool) \
@@ -461,9 +460,9 @@ AST_KIND(_DeclBegin,      "", bool) \
 		Ast *name; \
 	}) \
 	AST_KIND(ValueDecl, "value declaration", struct { \
-		Array<Ast *> names;       \
+		Slice<Ast *> names;       \
 		Ast *        type;        \
-		Array<Ast *> values;      \
+		Slice<Ast *> values;      \
 		Array<Ast *> attributes;  \
 		CommentGroup *docs;       \
 		CommentGroup *comment;    \
@@ -488,10 +487,10 @@ AST_KIND(_DeclBegin,      "", bool) \
 	}) \
 	AST_KIND(ForeignImportDecl, "foreign import declaration", struct { \
 		Token    token;           \
-		Array<Token> filepaths;   \
+		Slice<Token> filepaths;   \
 		Token    library_name;    \
 		String   collection_name; \
-		Array<String> fullpaths;  \
+		Slice<String> fullpaths;  \
 		Array<Ast *> attributes;  \
 		CommentGroup *docs;       \
 		CommentGroup *comment;    \
@@ -499,11 +498,11 @@ AST_KIND(_DeclBegin,      "", bool) \
 AST_KIND(_DeclEnd,   "", bool) \
 	AST_KIND(Attribute, "attribute", struct { \
 		Token token;        \
-		Array<Ast *> elems; \
+		Slice<Ast *> elems; \
 		Token open, close;  \
 	}) \
 	AST_KIND(Field, "field", struct { \
-		Array<Ast *> names;         \
+		Slice<Ast *> names;         \
 		Ast *        type;          \
 		Ast *        default_value; \
 		Token        tag;           \
@@ -513,7 +512,7 @@ AST_KIND(_DeclEnd,   "", bool) \
 	}) \
 	AST_KIND(FieldList, "field list", struct { \
 		Token token;       \
-		Array<Ast *> list; \
+		Slice<Ast *> list; \
 	}) \
 AST_KIND(_TypeBegin, "", bool) \
 	AST_KIND(TypeidType, "typeid", struct { \
@@ -567,34 +566,34 @@ AST_KIND(_TypeBegin, "", bool) \
 	}) \
 	AST_KIND(StructType, "struct type", struct { \
 		Token token;                \
-		Array<Ast *> fields;        \
+		Slice<Ast *> fields;        \
 		isize field_count;          \
 		Ast *polymorphic_params;    \
 		Ast *align;                 \
 		Token where_token;          \
-		Array<Ast *> where_clauses; \
+		Slice<Ast *> where_clauses; \
 		bool is_packed;             \
 		bool is_raw_union;          \
 	}) \
 	AST_KIND(UnionType, "union type", struct { \
 		Token        token;         \
-		Array<Ast *> variants;      \
+		Slice<Ast *> variants;      \
 		Ast *polymorphic_params;    \
 		Ast *        align;         \
 		bool         maybe;         \
 		bool         no_nil;        \
 		Token where_token;          \
-		Array<Ast *> where_clauses; \
+		Slice<Ast *> where_clauses; \
 	}) \
 	AST_KIND(EnumType, "enum type", struct { \
 		Token        token; \
 		Ast *        base_type; \
-		Array<Ast *> fields; /* FieldValue */ \
+		Slice<Ast *> fields; /* FieldValue */ \
 		bool         is_using; \
 	}) \
 	AST_KIND(BitFieldType, "bit field type", struct { \
 		Token        token; \
-		Array<Ast *> fields; /* FieldValue with : */ \
+		Slice<Ast *> fields; /* FieldValue with : */ \
 		Ast *        align; \
 	}) \
 	AST_KIND(BitSetType, "bit set type", struct { \