Add multi-pointer types `[^]T`

10 files changed, 286 insertions, 50 deletions

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 7c46ef4ca..68009882f 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -592,10 +592,25 @@ i64 check_distance_between_types(CheckerContext *c, Operand *operand, Type *type
 #if 1
 
 
-	// TODO(bill): Should I allow this implicit conversion at all?!
 	// rawptr <- ^T
 	if (are_types_identical(type, t_rawptr) && is_type_pointer(src)) {
-	    return 5;
+		return 5;
+	}
+	// rawptr <- [^]T
+	if (are_types_identical(type, t_rawptr) && is_type_multi_pointer(src)) {
+		return 5;
+	}
+	// ^T <- [^]T
+	if (is_type_pointer(dst) && is_type_multi_pointer(src)) {
+		if (are_types_identical(dst->Pointer.elem, src->MultiPointer.elem)) {
+			return 4;
+		}
+	}
+	// [^]T <- ^T
+	if (is_type_multi_pointer(dst) && is_type_pointer(src)) {
+		if (are_types_identical(dst->MultiPointer.elem, src->Pointer.elem)) {
+			return 4;
+		}
 	}
 #endif
 
@@ -2392,6 +2407,15 @@ bool check_is_castable_to(CheckerContext *c, Operand *operand, Type *y) {
 	if (is_type_pointer(src) && is_type_pointer(dst)) {
 		return true;
 	}
+	if (is_type_multi_pointer(src) && is_type_multi_pointer(dst)) {
+		return true;
+	}
+	if (is_type_multi_pointer(src) && is_type_pointer(dst)) {
+		return true;
+	}
+	if (is_type_pointer(src) && is_type_multi_pointer(dst)) {
+		return true;
+	}
 
 	// uintptr <-> pointer
 	if (is_type_uintptr(src) && is_type_pointer(dst)) {
@@ -2400,16 +2424,18 @@ bool check_is_castable_to(CheckerContext *c, Operand *operand, Type *y) {
 	if (is_type_pointer(src) && is_type_uintptr(dst)) {
 		return true;
 	}
+	if (is_type_uintptr(src) && is_type_multi_pointer(dst)) {
+		return true;
+	}
+	if (is_type_multi_pointer(src) && is_type_uintptr(dst)) {
+		return true;
+	}
 
 	// []byte/[]u8 <-> string (not cstring)
 	if (is_type_u8_slice(src) && (is_type_string(dst) && !is_type_cstring(dst))) {
 		return true;
 	}
-	if ((is_type_string(src) && !is_type_cstring(src)) && is_type_u8_slice(dst)) {
-		// if (is_type_typed(src)) {
-			// return true;
-		// }
-	}
+
 	// cstring -> string
 	if (are_types_identical(src, t_cstring) && are_types_identical(dst, t_string)) {
 		if (operand->mode != Addressing_Constant) {
@@ -2421,6 +2447,10 @@ bool check_is_castable_to(CheckerContext *c, Operand *operand, Type *y) {
 	if (are_types_identical(src, t_cstring) && is_type_u8_ptr(dst)) {
 		return !is_constant;
 	}
+	// cstring -> [^]u8
+	if (are_types_identical(src, t_cstring) && is_type_u8_multi_ptr(dst)) {
+		return !is_constant;
+	}
 	// cstring -> rawptr
 	if (are_types_identical(src, t_cstring) && is_type_rawptr(dst)) {
 		return !is_constant;
@@ -2430,6 +2460,10 @@ bool check_is_castable_to(CheckerContext *c, Operand *operand, Type *y) {
 	if (is_type_u8_ptr(src) && are_types_identical(dst, t_cstring)) {
 		return !is_constant;
 	}
+	// [^]u8 -> cstring
+	if (is_type_u8_multi_ptr(src) && are_types_identical(dst, t_cstring)) {
+		return !is_constant;
+	}
 	// rawptr -> cstring
 	if (is_type_rawptr(src) && are_types_identical(dst, t_cstring)) {
 		return !is_constant;
@@ -3328,7 +3362,7 @@ void convert_to_typed(CheckerContext *c, Operand *operand, Type *target_type) {
 	operand->type = target_type;
 }
 
-bool check_index_value(CheckerContext *c, bool open_range, Ast *index_value, i64 max_count, i64 *value, Type *type_hint=nullptr) {
+bool check_index_value(CheckerContext *c, Type *main_type, bool open_range, Ast *index_value, i64 max_count, i64 *value, Type *type_hint=nullptr) {
 	Operand operand = {Addressing_Invalid};
 	check_expr_with_type_hint(c, &operand, index_value, type_hint);
 	if (operand.mode == Addressing_Invalid) {
@@ -3367,7 +3401,7 @@ bool check_index_value(CheckerContext *c, bool open_range, Ast *index_value, i64
 	if (operand.mode == Addressing_Constant &&
 	    (c->state_flags & StateFlag_no_bounds_check) == 0) {
 		BigInt i = exact_value_to_integer(operand.value).value_integer;
-		if (i.sign && !is_type_enum(index_type)) {
+		if (i.sign && !is_type_enum(index_type) && !is_type_multi_pointer(main_type)) {
 			gbString expr_str = expr_to_string(operand.expr);
 			error(operand.expr, "Index '%s' cannot be a negative value", expr_str);
 			gb_string_free(expr_str);
@@ -6102,6 +6136,13 @@ bool check_set_index_data(Operand *o, Type *t, bool indirection, i64 *max_count,
 		}
 		break;
 
+	case Type_MultiPointer:
+		o->type = t->MultiPointer.elem;
+		if (o->mode != Addressing_Constant) {
+			o->mode = Addressing_Variable;
+		}
+		return true;
+
 	case Type_Array:
 		*max_count = t->Array.count;
 		if (indirection) {
@@ -8133,13 +8174,9 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 		}
 
 		i64 index = 0;
-		bool ok = check_index_value(c, false, ie->index, max_count, &index, index_type_hint);
+		bool ok = check_index_value(c, t, false, ie->index, max_count, &index, index_type_hint);
 		if (is_const) {
 			if (index < 0) {
-				if (max_count < 0) {
-
-				}
-
 				gbString str = expr_to_string(o->expr);
 				error(o->expr, "Cannot index a constant '%s'", str);
 				error_line("\tSuggestion: store the constant into a variable in order to index it with a variable index\n");
@@ -8206,6 +8243,11 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			o->type = alloc_type_slice(t->Array.elem);
 			break;
 
+		case Type_MultiPointer:
+			valid = true;
+			o->type = type_deref(o->type);
+			break;
+
 		case Type_Slice:
 			valid = true;
 			o->type = type_deref(o->type);
@@ -8262,7 +8304,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 					capacity = max_count;
 				}
 				i64 j = 0;
-				if (check_index_value(c, true, nodes[i], capacity, &j)) {
+				if (check_index_value(c, t, true, nodes[i], capacity, &j)) {
 					index = j;
 				}
 
@@ -8291,6 +8333,16 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			}
 		}
 
+		if (t->kind == Type_MultiPointer && se->high != nullptr) {
+			/*
+				x[:]   -> [^]T
+				x[i:]  -> [^]T
+				x[:n]  -> []T
+				x[i:n] -> []T
+			*/
+			o->type = alloc_type_slice(t->MultiPointer.elem);
+		}
+
 		o->mode = Addressing_Value;
 
 		if (is_type_string(t) && max_count >= 0) {
diff --git a/src/check_type.cpp b/src/check_type.cpp
index 867b4d7b2..3541eef61 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -2525,6 +2525,12 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 		return true;
 	case_end;
 
+	case_ast_node(pt, MultiPointerType, e);
+		*type = alloc_type_multi_pointer(check_type(ctx, pt->type));
+		set_base_type(named_type, *type);
+		return true;
+	case_end;
+
 	case_ast_node(rt, RelativeType, e);
 		GB_ASSERT(rt->tag->kind == Ast_CallExpr);
 		ast_node(ce, CallExpr, rt->tag);
diff --git a/src/checker.cpp b/src/checker.cpp
index 939872c0c..987d08e8d 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -1545,6 +1545,10 @@ void add_type_info_type_internal(CheckerContext *c, Type *t) {
 		add_type_info_type_internal(c, bt->Pointer.elem);
 		break;
 
+	case Type_MultiPointer:
+		add_type_info_type_internal(c, bt->MultiPointer.elem);
+		break;
+
 	case Type_Array:
 		add_type_info_type_internal(c, bt->Array.elem);
 		add_type_info_type_internal(c, alloc_type_pointer(bt->Array.elem));
@@ -1754,6 +1758,10 @@ void add_min_dep_type_info(Checker *c, Type *t) {
 		add_min_dep_type_info(c, bt->Pointer.elem);
 		break;
 
+	case Type_MultiPointer:
+		add_min_dep_type_info(c, bt->MultiPointer.elem);
+		break;
+
 	case Type_Array:
 		add_min_dep_type_info(c, bt->Array.elem);
 		add_min_dep_type_info(c, alloc_type_pointer(bt->Array.elem));
@@ -1993,6 +2001,7 @@ void generate_minimum_dependency_set(Checker *c, Entity *start) {
 			str_lit("bounds_check_error"),
 			str_lit("slice_expr_error_hi"),
 			str_lit("slice_expr_error_lo_hi"),
+			str_lit("multi_pointer_slice_expr_error"),
 		};
 		for (isize i = 0; i < gb_count_of(bounds_check_entities); i++) {
 			force_add_dependency_entity(c, c->info.runtime_package->scope, bounds_check_entities[i]);
@@ -2400,6 +2409,7 @@ void init_core_type_info(Checker *c) {
 	t_type_info_any              = find_core_type(c, str_lit("Type_Info_Any"));
 	t_type_info_typeid           = find_core_type(c, str_lit("Type_Info_Type_Id"));
 	t_type_info_pointer          = find_core_type(c, str_lit("Type_Info_Pointer"));
+	t_type_info_multi_pointer    = find_core_type(c, str_lit("Type_Info_Multi_Pointer"));
 	t_type_info_procedure        = find_core_type(c, str_lit("Type_Info_Procedure"));
 	t_type_info_array            = find_core_type(c, str_lit("Type_Info_Array"));
 	t_type_info_enumerated_array = find_core_type(c, str_lit("Type_Info_Enumerated_Array"));
@@ -2426,6 +2436,7 @@ void init_core_type_info(Checker *c) {
 	t_type_info_any_ptr              = alloc_type_pointer(t_type_info_any);
 	t_type_info_typeid_ptr           = alloc_type_pointer(t_type_info_typeid);
 	t_type_info_pointer_ptr          = alloc_type_pointer(t_type_info_pointer);
+	t_type_info_multi_pointer_ptr    = alloc_type_pointer(t_type_info_multi_pointer);
 	t_type_info_procedure_ptr        = alloc_type_pointer(t_type_info_procedure);
 	t_type_info_array_ptr            = alloc_type_pointer(t_type_info_array);
 	t_type_info_enumerated_array_ptr = alloc_type_pointer(t_type_info_enumerated_array);
diff --git a/src/llvm_backend_expr.cpp b/src/llvm_backend_expr.cpp
index c598fbf62..27517f7a3 100644
--- a/src/llvm_backend_expr.cpp
+++ b/src/llvm_backend_expr.cpp
@@ -1274,6 +1274,25 @@ lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
 		res.value = LLVMBuildPointerCast(p->builder, value.value, lb_type(m, t), "");
 		return res;
 	}
+	if (is_type_multi_pointer(src) && is_type_pointer(dst)) {
+		lbValue res = {};
+		res.type = t;
+		res.value = LLVMBuildPointerCast(p->builder, value.value, lb_type(m, t), "");
+		return res;
+	}
+	if (is_type_pointer(src) && is_type_multi_pointer(dst)) {
+		lbValue res = {};
+		res.type = t;
+		res.value = LLVMBuildPointerCast(p->builder, value.value, lb_type(m, t), "");
+		return res;
+	}
+	if (is_type_multi_pointer(src) && is_type_multi_pointer(dst)) {
+		lbValue res = {};
+		res.type = t;
+		res.value = LLVMBuildPointerCast(p->builder, value.value, lb_type(m, t), "");
+		return res;
+	}
+
 
 
 
@@ -2838,6 +2857,21 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 			return lb_addr(v);
 		}
 
+		case Type_MultiPointer: {
+			lbValue multi_ptr = {};
+			multi_ptr = lb_build_expr(p, ie->expr);
+			if (deref) {
+				multi_ptr = lb_emit_load(p, multi_ptr);
+			}
+			lbValue index = lb_build_expr(p, ie->index);
+			lbValue v = {};
+
+			LLVMValueRef indices[1] = {index.value};
+			v.value = LLVMBuildGEP(p->builder, multi_ptr.value, indices, 1, "");
+			v.type = t;
+			return lb_addr(v);
+		}
+
 		case Type_RelativeSlice: {
 			lbAddr slice_addr = {};
 			if (deref) {
@@ -2952,6 +2986,27 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 			return slice;
 		}
 
+		case Type_MultiPointer: {
+			lbAddr res = lb_add_local_generated(p, type_of_expr(expr), false);
+			if (se->high == nullptr) {
+				lbValue offset = base;
+				LLVMValueRef indices[1] = {low.value};
+				offset.value = LLVMBuildGEP(p->builder, offset.value, indices, 1, "");
+				lb_addr_store(p, res, offset);
+			} else {
+				lb_emit_multi_pointer_slice_bounds_check(p, se->open, low, high);
+
+				LLVMValueRef indices[1] = {low.value};
+				LLVMValueRef ptr = LLVMBuildGEP(p->builder, base.value, indices, 1, "");
+				LLVMValueRef len = LLVMBuildSub(p->builder, high.value, low.value, "");
+				// TODO(bill): bounds_check for negative length
+				LLVMValueRef gep0 = lb_emit_struct_ep(p, res.addr, 0).value;
+				LLVMValueRef gep1 = lb_emit_struct_ep(p, res.addr, 1).value;
+				LLVMBuildStore(p->builder, ptr, gep0);
+				LLVMBuildStore(p->builder, len, gep1);
+			}
+			return res;
+		}
 
 		case Type_Array: {
 			Type *slice_type = alloc_type_slice(type->Array.elem);
diff --git a/src/llvm_backend_general.cpp b/src/llvm_backend_general.cpp
index 20b3aba25..94fe1e562 100644
--- a/src/llvm_backend_general.cpp
+++ b/src/llvm_backend_general.cpp
@@ -420,6 +420,31 @@ void lb_emit_bounds_check(lbProcedure *p, Token token, lbValue index, lbValue le
 	lb_emit_runtime_call(p, "bounds_check_error", args);
 }
 
+void lb_emit_multi_pointer_slice_bounds_check(lbProcedure *p, Token token, lbValue low, lbValue high) {
+	if (build_context.no_bounds_check) {
+		return;
+	}
+	if ((p->state_flags & StateFlag_no_bounds_check) != 0) {
+		return;
+	}
+
+	low = lb_emit_conv(p, low, t_int);
+	high = lb_emit_conv(p, high, t_int);
+
+	lbValue file = lb_find_or_add_entity_string(p->module, get_file_path_string(token.pos.file_id));
+	lbValue line = lb_const_int(p->module, t_i32, token.pos.line);
+	lbValue column = lb_const_int(p->module, t_i32, token.pos.column);
+
+	auto args = array_make<lbValue>(permanent_allocator(), 5);
+	args[0] = file;
+	args[1] = line;
+	args[2] = column;
+	args[3] = low;
+	args[4] = high;
+
+	lb_emit_runtime_call(p, "multi_pointer_slice_expr_error", args);
+}
+
 void lb_emit_slice_bounds_check(lbProcedure *p, Token token, lbValue low, lbValue high, lbValue len, bool lower_value_used) {
 	if (build_context.no_bounds_check) {
 		return;
@@ -810,6 +835,13 @@ LLVMTypeRef llvm_addr_type(lbValue addr_val) {
 
 lbValue lb_emit_load(lbProcedure *p, lbValue value) {
 	GB_ASSERT(value.value != nullptr);
+	if (is_type_multi_pointer(value.type)) {
+		Type *vt = base_type(value.type);
+		GB_ASSERT(vt->kind == Type_MultiPointer);
+		Type *t = vt->MultiPointer.elem;
+		LLVMValueRef v = LLVMBuildLoad2(p->builder, llvm_addr_type(value), value.value, "");
+		return lbValue{v, t};
+	}
 	GB_ASSERT(is_type_pointer(value.type));
 	Type *t = type_deref(value.type);
 	LLVMValueRef v = LLVMBuildLoad2(p->builder, llvm_addr_type(value), value.value, "");
@@ -1568,6 +1600,9 @@ LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 	case Type_Pointer:
 		return LLVMPointerType(lb_type(m, type->Pointer.elem), 0);
 
+	case Type_MultiPointer:
+		return LLVMPointerType(lb_type(m, type->Pointer.elem), 0);
+
 	case Type_Array: {
 		m->internal_type_level -= 1;
 		LLVMTypeRef t = LLVMArrayType(lb_type(m, type->Array.elem), cast(unsigned)type->Array.count);
diff --git a/src/llvm_backend_type.cpp b/src/llvm_backend_type.cpp
index d58ab1c77..af3fadc3c 100644
--- a/src/llvm_backend_type.cpp
+++ b/src/llvm_backend_type.cpp
@@ -40,6 +40,7 @@ lbValue lb_typeid(lbModule *m, Type *type) {
 		if (flags & BasicFlag_Rune)     kind = Typeid_Rune;
 	} break;
 	case Type_Pointer:         kind = Typeid_Pointer;          break;
+	case Type_MultiPointer:    kind = Typeid_Multi_Pointer;    break;
 	case Type_Array:           kind = Typeid_Array;            break;
 	case Type_EnumeratedArray: kind = Typeid_Enumerated_Array; break;
 	case Type_Slice:           kind = Typeid_Slice;            break;
@@ -396,6 +397,20 @@ void lb_setup_type_info_data(lbProcedure *p) { // NOTE(bill): Setup type_info da
 			lb_emit_store(p, tag, res);
 			break;
 		}
+		case Type_MultiPointer: {
+			tag = lb_const_ptr_cast(m, variant_ptr, t_type_info_multi_pointer_ptr);
+			lbValue gep = lb_get_type_info_ptr(m, t->MultiPointer.elem);
+
+			LLVMValueRef vals[1] = {
+				gep.value,
+			};
+
+			lbValue res = {};
+			res.type = type_deref(tag.type);
+			res.value = llvm_const_named_struct(lb_type(m, res.type), vals, gb_count_of(vals));
+			lb_emit_store(p, tag, res);
+			break;
+		}
 		case Type_Array: {
 			tag = lb_const_ptr_cast(m, variant_ptr, t_type_info_array_ptr);
 			i64 ez = type_size_of(t->Array.elem);
diff --git a/src/parser.cpp b/src/parser.cpp
index 6184a62ab..898dd4da6 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -337,6 +337,9 @@ Ast *clone_ast(Ast *node) {
 	case Ast_PointerType:
 		n->PointerType.type = clone_ast(n->PointerType.type);
 		break;
+	case Ast_MultiPointerType:
+		n->MultiPointerType.type = clone_ast(n->MultiPointerType.type);
+		break;
 	case Ast_ArrayType:
 		n->ArrayType.count = clone_ast(n->ArrayType.count);
 		n->ArrayType.elem  = clone_ast(n->ArrayType.elem);
@@ -985,7 +988,12 @@ Ast *ast_pointer_type(AstFile *f, Token token, Ast *type) {
 	result->PointerType.type = type;
 	return result;
 }
-
+Ast *ast_multi_pointer_type(AstFile *f, Token token, Ast *type) {
+	Ast *result = alloc_ast_node(f, Ast_MultiPointerType);
+	result->MultiPointerType.token = token;
+	result->MultiPointerType.type = type;
+	return result;
+}
 Ast *ast_array_type(AstFile *f, Token token, Ast *count, Ast *elem) {
 	Ast *result = alloc_ast_node(f, Ast_ArrayType);
 	result->ArrayType.token = token;
@@ -2317,7 +2325,11 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 	case Token_OpenBracket: {
 		Token token = expect_token(f, Token_OpenBracket);
 		Ast *count_expr = nullptr;
-		if (f->curr_token.kind == Token_Question) {
+		if (f->curr_token.kind == Token_Pointer) {
+			expect_token(f, Token_Pointer);
+			expect_token(f, Token_CloseBracket);
+			return ast_multi_pointer_type(f, token, parse_type(f));
+		} else if (f->curr_token.kind == Token_Question) {
 			count_expr = ast_unary_expr(f, expect_token(f, Token_Question), nullptr);
 		} else if (allow_token(f, Token_dynamic)) {
 			expect_token(f, Token_CloseBracket);
diff --git a/src/parser.hpp b/src/parser.hpp
index 3612d5e96..1b45024b6 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -604,6 +604,10 @@ AST_KIND(_TypeBegin, "", bool) \
 		Ast *tag; \
 		Ast *type; \
 	}) \
+	AST_KIND(MultiPointerType, "multi pointer type", struct { \
+		Token token; \
+		Ast *type; \
+	}) \
 	AST_KIND(ArrayType, "array type", struct { \
 		Token token; \
 		Ast *count; \
diff --git a/src/parser_pos.cpp b/src/parser_pos.cpp
index 0f2ac438a..8d164caf9 100644
--- a/src/parser_pos.cpp
+++ b/src/parser_pos.cpp
@@ -95,6 +95,7 @@ Token ast_token(Ast *node) {
 	case Ast_ProcType:         return node->ProcType.token;
 	case Ast_RelativeType:     return ast_token(node->RelativeType.tag);
 	case Ast_PointerType:      return node->PointerType.token;
+	case Ast_MultiPointerType: return node->MultiPointerType.token;
 	case Ast_ArrayType:        return node->ArrayType.token;
 	case Ast_DynamicArrayType: return node->DynamicArrayType.token;
 	case Ast_StructType:       return node->StructType.token;
@@ -312,6 +313,7 @@ Token ast_end_token(Ast *node) {
 	case Ast_RelativeType:
 		return ast_end_token(node->RelativeType.type);
 	case Ast_PointerType:      return ast_end_token(node->PointerType.type);
+	case Ast_MultiPointerType: return ast_end_token(node->MultiPointerType.type);
 	case Ast_ArrayType:        return ast_end_token(node->ArrayType.elem);
 	case Ast_DynamicArrayType: return ast_end_token(node->DynamicArrayType.elem);
 	case Ast_StructType:
diff --git a/src/types.cpp b/src/types.cpp
index b8a20173b..37a05d5a6 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -192,47 +192,48 @@ struct TypeProc {
 	bool     optional_ok;
 };
 
-#define TYPE_KINDS                                        \
-	TYPE_KIND(Basic, BasicType)                           \
-	TYPE_KIND(Named, struct {                             \
+#define TYPE_KINDS                                                \
+	TYPE_KIND(Basic, BasicType)                               \
+	TYPE_KIND(Named, struct {                                 \
 		String  name;                                     \
 		Type *  base;                                     \
 		Entity *type_name; /* Entity_TypeName */          \
-	})                                                    \
-	TYPE_KIND(Generic, struct {                           \
+	})                                                        \
+	TYPE_KIND(Generic, struct {                               \
 		i64     id;                                       \
 		String  name;                                     \
 		Type *  specialized;                              \
 		Scope * scope;                                    \
 		Entity *entity;                                   \
-	})                                                    \
-	TYPE_KIND(Pointer, struct { Type *elem; })            \
-	TYPE_KIND(Array,   struct {                           \
+	})                                                        \
+	TYPE_KIND(Pointer, struct { Type *elem; })                \
+	TYPE_KIND(MultiPointer, struct { Type *elem; })           \
+	TYPE_KIND(Array,   struct {                               \
 		Type *elem;                                       \
 		i64   count;                                      \
 		Type *generic_count;                              \
-	})                                                    \
-	TYPE_KIND(EnumeratedArray, struct {                   \
+	})                                                        \
+	TYPE_KIND(EnumeratedArray, struct {                       \
 		Type *elem;                                       \
 		Type *index;                                      \
 		ExactValue min_value;                             \
 		ExactValue max_value;                             \
 		i64 count;                                        \
 		TokenKind op;                                     \
-	})                                                    \
-	TYPE_KIND(Slice,   struct { Type *elem; })            \
-	TYPE_KIND(DynamicArray, struct { Type *elem; })       \
-	TYPE_KIND(Map, struct {                               \
+	})                                                        \
+	TYPE_KIND(Slice,   struct { Type *elem; })                \
+	TYPE_KIND(DynamicArray, struct { Type *elem; })           \
+	TYPE_KIND(Map, struct {                                   \
 		Type *key;                                        \
 		Type *value;                                      \
 		Type *entry_type;                                 \
 		Type *generated_struct_type;                      \
 		Type *internal_type;                              \
 		Type *lookup_result_type;                         \
-	})                                                    \
-	TYPE_KIND(Struct,  TypeStruct)                        \
-	TYPE_KIND(Union,   TypeUnion)                         \
-	TYPE_KIND(Enum, struct {                              \
+	})                                                        \
+	TYPE_KIND(Struct,  TypeStruct)                            \
+	TYPE_KIND(Union,   TypeUnion)                             \
+	TYPE_KIND(Enum, struct {                                  \
 		Array<Entity *> fields;                           \
 		Ast *node;                                        \
 		Scope *  scope;                                   \
@@ -242,31 +243,31 @@ struct TypeProc {
 		ExactValue max_value;                             \
 		isize min_value_index;                            \
 		isize max_value_index;                            \
-	})                                                    \
-	TYPE_KIND(Tuple, struct {                             \
+	})                                                        \
+	TYPE_KIND(Tuple, struct {                                 \
 		Array<Entity *> variables; /* Entity_Variable */  \
 		Array<i64>      offsets;                          \
 		bool            are_offsets_being_processed;      \
 		bool            are_offsets_set;                  \
 		bool            is_packed;                        \
-	})                                                    \
-	TYPE_KIND(Proc, TypeProc)                             \
-	TYPE_KIND(BitSet, struct {                            \
+	})                                                        \
+	TYPE_KIND(Proc, TypeProc)                                 \
+	TYPE_KIND(BitSet, struct {                                \
 		Type *elem;                                       \
 		Type *underlying;                                 \
 		i64   lower;                                      \
 		i64   upper;                                      \
 		Ast * node;                                       \
-	})                                                    \
-	TYPE_KIND(SimdVector, struct {                        \
+	})                                                        \
+	TYPE_KIND(SimdVector, struct {                            \
 		i64   count;                                      \
 		Type *elem;                                       \
-	})                                                    \
-	TYPE_KIND(RelativePointer, struct {                   \
+	})                                                        \
+	TYPE_KIND(RelativePointer, struct {                       \
 		Type *pointer_type;                               \
 		Type *base_integer;                               \
-	})                                                    \
-	TYPE_KIND(RelativeSlice, struct {                     \
+	})                                                        \
+	TYPE_KIND(RelativeSlice, struct {                         \
 		Type *slice_type;                                 \
 		Type *base_integer;                               \
 	})
@@ -325,6 +326,7 @@ enum Typeid_Kind : u8 {
 	Typeid_Any,
 	Typeid_Type_Id,
 	Typeid_Pointer,
+	Typeid_Multi_Pointer,
 	Typeid_Procedure,
 	Typeid_Array,
 	Typeid_Enumerated_Array,
@@ -605,6 +607,7 @@ gb_global Type *t_type_info_typeid               = nullptr;
 gb_global Type *t_type_info_string               = nullptr;
 gb_global Type *t_type_info_boolean              = nullptr;
 gb_global Type *t_type_info_pointer              = nullptr;
+gb_global Type *t_type_info_multi_pointer        = nullptr;
 gb_global Type *t_type_info_procedure            = nullptr;
 gb_global Type *t_type_info_array                = nullptr;
 gb_global Type *t_type_info_enumerated_array     = nullptr;
@@ -631,6 +634,7 @@ gb_global Type *t_type_info_typeid_ptr           = nullptr;
 gb_global Type *t_type_info_string_ptr           = nullptr;
 gb_global Type *t_type_info_boolean_ptr          = nullptr;
 gb_global Type *t_type_info_pointer_ptr          = nullptr;
+gb_global Type *t_type_info_multi_pointer_ptr    = nullptr;
 gb_global Type *t_type_info_procedure_ptr        = nullptr;
 gb_global Type *t_type_info_array_ptr            = nullptr;
 gb_global Type *t_type_info_enumerated_array_ptr = nullptr;
@@ -779,6 +783,12 @@ Type *alloc_type_pointer(Type *elem) {
 	return t;
 }
 
+Type *alloc_type_multi_pointer(Type *elem) {
+	Type *t = alloc_type(Type_MultiPointer);
+	t->MultiPointer.elem = elem;
+	return t;
+}
+
 Type *alloc_type_array(Type *elem, i64 count, Type *generic_count = nullptr) {
 	if (generic_count != nullptr) {
 		Type *t = alloc_type(Type_Array);
@@ -948,10 +958,10 @@ Type *type_deref(Type *t) {
 		if (bt == nullptr) {
 			return nullptr;
 		}
-		if (bt != nullptr && bt->kind == Type_Pointer) {
+		if (bt->kind == Type_Pointer) {
 			return bt->Pointer.elem;
 		}
-		if (bt != nullptr && bt->kind == Type_RelativePointer) {
+		if (bt->kind == Type_RelativePointer) {
 			return type_deref(bt->RelativePointer.pointer_type);
 		}
 	}
@@ -1084,6 +1094,8 @@ bool is_type_ordered(Type *t) {
 		return (t->Basic.flags & BasicFlag_Ordered) != 0;
 	case Type_Pointer:
 		return true;
+	case Type_MultiPointer:
+		return true;
 	}
 	return false;
 }
@@ -1157,6 +1169,10 @@ bool is_type_pointer(Type *t) {
 	}
 	return t->kind == Type_Pointer;
 }
+bool is_type_multi_pointer(Type *t) {
+	t = base_type(t);
+	return t->kind == Type_MultiPointer;
+}
 bool is_type_tuple(Type *t) {
 	t = base_type(t);
 	return t->kind == Type_Tuple;
@@ -1259,6 +1275,13 @@ bool is_type_u8_ptr(Type *t) {
 	}
 	return false;
 }
+bool is_type_u8_multi_ptr(Type *t) {
+	t = base_type(t);
+	if (t->kind == Type_MultiPointer) {
+		return is_type_u8(t->Slice.elem);
+	}
+	return false;
+}
 bool is_type_rune_array(Type *t) {
 	t = base_type(t);
 	if (t->kind == Type_Array) {
@@ -1348,7 +1371,8 @@ bool is_type_union_maybe_pointer(Type *t) {
 	t = base_type(t);
 	if (t->kind == Type_Union && t->Union.maybe) {
 		if (t->Union.variants.count == 1) {
-			return is_type_pointer(t->Union.variants[0]);
+			Type *v = t->Union.variants[0];
+			return is_type_pointer(v) || is_type_multi_pointer(v);
 		}
 	}
 	return false;
@@ -1360,7 +1384,7 @@ bool is_type_union_maybe_pointer_original_alignment(Type *t) {
 	if (t->kind == Type_Union && t->Union.maybe) {
 		if (t->Union.variants.count == 1) {
 			Type *v = t->Union.variants[0];
-			if (is_type_pointer(v)) {
+			if (is_type_pointer(v) || is_type_multi_pointer(v)) {
 				return type_align_of(v) == type_align_of(t);
 			}
 		}
@@ -1614,6 +1638,8 @@ bool is_type_indexable(Type *t) {
 	case Type_DynamicArray:
 	case Type_Map:
 		return true;
+	case Type_MultiPointer:
+		return true;
 	case Type_EnumeratedArray:
 		return true;
 	case Type_RelativeSlice:
@@ -1836,6 +1862,7 @@ bool type_has_nil(Type *t) {
 	case Type_Slice:
 	case Type_Proc:
 	case Type_Pointer:
+	case Type_MultiPointer:
 	case Type_DynamicArray:
 	case Type_Map:
 		return true;
@@ -1890,6 +1917,8 @@ bool is_type_comparable(Type *t) {
 		return true;
 	case Type_Pointer:
 		return true;
+	case Type_MultiPointer:
+		return true;
 	case Type_Enum:
 		return is_type_comparable(core_type(t));
 	case Type_EnumeratedArray:
@@ -1955,6 +1984,7 @@ bool is_type_simple_compare(Type *t) {
 		return false;
 
 	case Type_Pointer:
+	case Type_MultiPointer:
 	case Type_Proc:
 	case Type_BitSet:
 		return true;
@@ -2157,6 +2187,12 @@ bool are_types_identical(Type *x, Type *y) {
 		}
 		break;
 
+	case Type_MultiPointer:
+		if (y->kind == Type_MultiPointer) {
+			return are_types_identical(x->MultiPointer.elem, y->MultiPointer.elem);
+		}
+		break;
+
 	case Type_Named:
 		if (y->kind == Type_Named) {
 			return x->Named.type_name == y->Named.type_name;
@@ -3139,6 +3175,9 @@ i64 type_size_of_internal(Type *t, TypePath *path) {
 	case Type_Pointer:
 		return build_context.word_size;
 
+	case Type_MultiPointer:
+		return build_context.word_size;
+
 	case Type_Array: {
 		i64 count, align, size, alignment;
 		count = t->Array.count;
@@ -3509,6 +3548,11 @@ gbString write_type_to_string(gbString str, Type *type) {
 		str = write_type_to_string(str, type->Pointer.elem);
 		break;
 
+	case Type_MultiPointer:
+		str = gb_string_appendc(str, "[^]");
+		str = write_type_to_string(str, type->Pointer.elem);
+		break;
+
 	case Type_EnumeratedArray:
 		str = gb_string_append_rune(str, '[');
 		str = write_type_to_string(str, type->EnumeratedArray.index);