diff --git a/base/runtime/core_builtin_soa.odin b/base/runtime/core_builtin_soa.odin
index 1b2e5d316..94f5be1d4 100644
--- a/base/runtime/core_builtin_soa.odin
+++ b/base/runtime/core_builtin_soa.odin
@@ -86,7 +86,6 @@ make_soa_aligned :: proc($T: typeid/#soa[]$E, length: int, alignment: int, alloc
 		return
 	}
 
-	array.allocator = allocator
 	footer := raw_soa_footer(&array)
 	if size_of(E) == 0 {
 		footer.len = length
diff --git a/core/relative/relative.odin b/core/relative/relative.odin
new file mode 100644
index 000000000..30a7b86ae
--- /dev/null
+++ b/core/relative/relative.odin
@@ -0,0 +1,171 @@
+package relative_types
+
+import "base:intrinsics"
+
+Pointer :: struct($Type: typeid, $Backing: typeid)
+	where
+		intrinsics.type_is_pointer(Type) || intrinsics.type_is_multi_pointer(Type),
+		intrinsics.type_is_integer(Backing) {
+	offset: Backing,
+}
+
+Slice :: struct($Type: typeid, $Backing: typeid)
+	where
+		intrinsics.type_is_slice(Type),
+		intrinsics.type_is_integer(Backing) {
+	offset: Backing,
+	len:    Backing,
+}
+
+
+
+@(require_results)
+pointer_get :: proc "contextless" (p: ^$P/Pointer($T, $B)) -> T {
+	if p.offset == 0 {
+		return nil
+	}
+	ptr := ([^]byte)(p)[p.offset:]
+	return (T)(ptr)
+}
+
+pointer_set :: proc "contextless" (p: ^$P/Pointer($T, $B), ptr: T) {
+	if ptr == nil {
+		p.offset = 0
+	} else {
+		p.offset = B(int(uintptr(ptr)) - int(uintptr(p)))
+	}
+}
+
+@(require_results)
+slice_get :: proc "contextless" (p: ^$S/Slice($T/[]$E, $B)) -> (slice: T) {
+	if p.offset == 0 {
+		when size_of(E) == 0 {
+			slice = T(([^]E)(nil)[:p.len])
+		}
+	} else {
+		ptr := ([^]E)(([^]byte)(p)[p.offset:])
+		slice = T(ptr[:p.len])
+	}
+	return
+}
+
+slice_set :: proc "contextless" (p: ^$S/Slice($T, $B), slice: T) {
+	if slice == nil {
+		p.offset, p.len = 0, 0
+	} else {
+		ptr := raw_data(slice)
+		p.offset = B(int(uintptr(ptr)) - int(uintptr(p)))
+		p.len    = B(len(slice))
+	}
+}
+
+get :: proc{
+	pointer_get,
+	slice_get,
+}
+
+set :: proc{
+	pointer_set,
+	slice_set,
+}
+
+
+
+Set_Safe_Error :: enum {
+	None,
+	Memory_Too_Far_Apart,
+	Length_Out_Of_Bounds,
+}
+
+
+@(require_results)
+pointer_set_safe :: proc "contextless" (p: ^$P/Pointer($T, $B), ptr: T) -> Set_Safe_Error {
+	if ptr == nil {
+		p.offset = 0
+	} else {
+		when intrinsics.type_is_unsigned(B) {
+			diff := uint(uintptr(ptr) - uintptr(p))
+			when size_of(B) < size_of(uint) {
+				if diff > uint(max(B)) {
+					return .Memory_Too_Far_Apart
+				}
+			} else {
+				if B(diff) > max(B) {
+					return .Memory_Too_Far_Apart
+				}
+			}
+		} else {
+			diff := int(uintptr(ptr)) - int(uintptr(p))
+			when size_of(B) < size_of(int) {
+				if diff > int(max(B)) {
+					return .Memory_Too_Far_Apart
+				}
+			} else {
+				if B(diff) > max(B) {
+					return .Memory_Too_Far_Apart
+				}
+			}
+		}
+		p.offset = B(diff)
+	}
+	return .None
+}
+
+@(require_results)
+slice_set_safe :: proc "contextless" (p: ^$S/Slice($T, $B), slice: T) -> Set_Safe_Error {
+	if slice == nil {
+		p.offset, p.len = 0, 0
+	} else {
+		ptr := raw_data(slice)
+		when intrinsics.type_is_unsigned(B) {
+			diff := uint(uintptr(ptr) - uintptr(p))
+			when size_of(B) < size_of(uint) {
+				if diff > uint(max(B)) {
+					return .Memory_Too_Far_Apart
+				}
+
+				if uint(len(slice)) > uint(max(B)) {
+					return .Length_Out_Of_Bounds
+				}
+			} else {
+				if B(diff) > max(B) {
+					return .Memory_Too_Far_Apart
+				}
+				if B(len(slice)) > max(B) {
+					return .Length_Out_Of_Bounds
+				}
+			}
+			p.offset = B(diff)
+			p.len = B(len(slice))
+		} else {
+			diff := int(uintptr(ptr)) - int(uintptr(p))
+			when size_of(B) < size_of(int) {
+				if diff > int(max(B)) {
+					return .Memory_Too_Far_Apart
+				}
+				if len(slice) > int(max(B)) || len(slice) < int(min(B)) {
+					return .Length_Out_Of_Bounds
+				}
+			} else {
+				if B(diff) > max(B) {
+					return .Memory_Too_Far_Apart
+				}
+				if B(len(slice)) > max(B) {
+					return .Length_Out_Of_Bounds
+				}
+				if B(len(slice)) > max(B) || B(len(slice)) < min(B) {
+					return .Length_Out_Of_Bounds
+				}
+			}
+		}
+		p.offset = B(diff)
+		p.len = B(len(slice))
+	}
+	return .None
+}
+
+
+set_safe :: proc{
+	pointer_set_safe,
+	slice_set_safe,
+}
\ No newline at end of file
diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index e1cb43ec1..4e374add6 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -5686,7 +5686,7 @@ gb_internal bool check_builtin_procedure(CheckerContext *c, Operand *operand, As
 				return false;
 			}
 
-			operand->value = exact_value_bool(is_type_subtype_of(op_src.type, op_dst.type));
+			operand->value = exact_value_bool(is_type_subtype_of_and_allow_polymorphic(op_src.type, op_dst.type));
 			operand->mode = Addressing_Constant;
 			operand->type = t_untyped_bool;
 		} break;
diff --git a/src/check_type.cpp b/src/check_type.cpp
index 0a2113e56..d216ae3e6 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -1,4 +1,6 @@
 gb_internal ParameterValue handle_parameter_value(CheckerContext *ctx, Type *in_type, Type **out_type_, Ast *expr, bool allow_caller_location);
+gb_internal Type *determine_type_from_polymorphic(CheckerContext *ctx, Type *poly_type, Operand const &operand);
+gb_internal Type *check_get_params(CheckerContext *ctx, Scope *scope, Ast *_params, bool *is_variadic_, isize *variadic_index_, bool *success_, isize *specialization_count_, Array<Operand> const *operands);
 
 gb_internal void populate_using_array_index(CheckerContext *ctx, Ast *node, AstField *field, Type *t, String name, i32 idx) {
 	t = base_type(t);
@@ -393,7 +395,6 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
                                                   bool *is_polymorphic_,
                                                   Ast *node, Array<Operand> *poly_operands) {
 	Type *polymorphic_params_type = nullptr;
-	bool can_check_fields = true;
 	GB_ASSERT(is_polymorphic_ != nullptr);
 
 	if (polymorphic_params == nullptr) {
@@ -403,6 +404,17 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
 		return polymorphic_params_type;
 	}
 
+
+	// bool is_variadic = false;
+	// isize variadic_index = 0;
+	// bool success = false;
+	// isize specialization_count = 0;
+	// polymorphic_params_type = check_get_params(ctx, ctx->scope, polymorphic_params, &is_variadic, &variadic_index, &success, &specialization_count, poly_operands);
+	// if (success) {
+	// 	return nullptr;
+	// }
+
+	bool can_check_fields = true;
 	ast_node(field_list, FieldList, polymorphic_params);
 	Slice<Ast *> params = field_list->list;
 	if (params.count != 0) {
@@ -417,11 +429,13 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
 
 		auto entities = array_make<Entity *>(permanent_allocator(), 0, variable_count);
 
+		i32 field_group_index = -1;
 		for_array(i, params) {
 			Ast *param = params[i];
 			if (param->kind != Ast_Field) {
 				continue;
 			}
+			field_group_index += 1;
 			ast_node(p, Field, param);
 			Ast *type_expr = p->type;
 			Ast *default_value = unparen_expr(p->default_value);
@@ -481,7 +495,7 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
 				type = t_invalid;
 			}
 
-			if (is_type_polymorphic_type) {
+			if (is_type_polymorphic_type && !is_type_proc(type)) {
 				gbString str = type_to_string(type);
 				error(params[i], "Parameter types cannot be polymorphic, got %s", str);
 				gb_string_free(str);
@@ -523,13 +537,18 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
 						e->TypeName.is_type_alias = true;
 						e->flags |= EntityFlag_PolyConst;
 					} else {
-						if (is_type_polymorphic(base_type(operand.type))) {
+						Type *t = operand.type;
+						if (is_type_proc(type)) {
+							t = determine_type_from_polymorphic(ctx, type, operand);
+						}
+						if (is_type_polymorphic(base_type(t))) {
 							*is_polymorphic_ = true;
 							can_check_fields = false;
 						}
 						if (e == nullptr) {
-							e = alloc_entity_constant(scope, token, operand.type, operand.value);
+							e = alloc_entity_const_param(scope, token, t, operand.value, is_type_polymorphic(t));
 							e->Constant.param_value = param_value;
+							e->Constant.field_group_index = field_group_index;
 						}
 					}
 				} else {
@@ -538,7 +557,8 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
 						e->TypeName.is_type_alias = true;
 						e->flags |= EntityFlag_PolyConst;
 					} else {
-						e = alloc_entity_constant(scope, token, type, param_value.value);
+						e = alloc_entity_const_param(scope, token, type, param_value.value, is_type_polymorphic(type));
+						e->Constant.field_group_index = field_group_index;
 						e->Constant.param_value = param_value;
 					}
 				}
@@ -559,7 +579,6 @@ gb_internal Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *poly
 	if (!*is_polymorphic_) {
 		*is_polymorphic_ = polymorphic_params != nullptr && poly_operands == nullptr;
 	}
-
 	return polymorphic_params_type;
 }
 
diff --git a/src/parser.cpp b/src/parser.cpp
index 2a7f41b36..78ac29dfd 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -2164,6 +2164,49 @@ gb_internal Array<Ast *> parse_union_variant_list(AstFile *f) {
 	return variants;
 }
 
+gb_internal void parser_check_polymorphic_record_parameters(AstFile *f, Ast *polymorphic_params) {
+	if (polymorphic_params == nullptr) {
+		return;
+	}
+	if (polymorphic_params->kind != Ast_FieldList) {
+		return;
+	}
+
+
+	enum {Unknown, Dollar, Bare} prefix = Unknown;
+	gb_unused(prefix);
+
+	for (Ast *field : polymorphic_params->FieldList.list) {
+		if (field == nullptr || field->kind != Ast_Field) {
+			continue;
+		}
+		for (Ast *name : field->Field.names) {
+			if (name == nullptr) {
+				continue;
+			}
+			bool error = false;
+
+			if (name->kind == Ast_Ident) {
+				switch (prefix) {
+				case Unknown: prefix = Bare; break;
+				case Dollar:  error = true;  break;
+				case Bare:                   break;
+				}
+			} else if (name->kind == Ast_PolyType) {
+				switch (prefix) {
+				case Unknown: prefix = Dollar; break;
+				case Dollar:                   break;
+				case Bare:    error = true;    break;
+				}
+			}
+			if (error) {
+				syntax_error(name, "Mixture of polymorphic $ names and normal identifiers are not allowed within record parameters");
+			}
+		}
+	}
+}
+
+
 gb_internal Ast *parse_operand(AstFile *f, bool lhs) {
 	Ast *operand = nullptr; // Operand
 	switch (f->curr_token.kind) {
@@ -2610,6 +2653,8 @@ gb_internal Ast *parse_operand(AstFile *f, bool lhs) {
 			decls = fields->FieldList.list;
 		}
 
+		parser_check_polymorphic_record_parameters(f, polymorphic_params);
+
 		return ast_struct_type(f, token, decls, name_count, polymorphic_params, is_packed, is_raw_union, no_copy, align, field_align, where_token, where_clauses);
 	} break;
 
@@ -2702,6 +2747,8 @@ gb_internal Ast *parse_operand(AstFile *f, bool lhs) {
 		auto variants = parse_union_variant_list(f);
 		Token close = expect_closing_brace_of_field_list(f);
 
+		parser_check_polymorphic_record_parameters(f, polymorphic_params);
+
 		return ast_union_type(f, token, variants, polymorphic_params, align, union_kind, where_token, where_clauses);
 	} break;
 
diff --git a/src/types.cpp b/src/types.cpp
index b99d469e4..c4b03c967 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -4093,7 +4093,7 @@ gb_internal i64 type_offset_of_from_selection(Type *type, Selection sel) {
 	return offset;
 }
 
-gb_internal isize check_is_assignable_to_using_subtype(Type *src, Type *dst, isize level = 0, bool src_is_ptr = false) {
+gb_internal isize check_is_assignable_to_using_subtype(Type *src, Type *dst, isize level = 0, bool src_is_ptr = false, bool allow_polymorphic=false) {
 	Type *prev_src = src;
 	src = type_deref(src);
 	if (!src_is_ptr) {
@@ -4105,11 +4105,19 @@ gb_internal isize check_is_assignable_to_using_subtype(Type *src, Type *dst, isi
 		return 0;
 	}
 
+	bool dst_is_polymorphic = is_type_polymorphic(dst);
+
 	for_array(i, src->Struct.fields) {
 		Entity *f = src->Struct.fields[i];
 		if (f->kind != Entity_Variable || (f->flags&EntityFlags_IsSubtype) == 0) {
 			continue;
 		}
+		if (allow_polymorphic && dst_is_polymorphic) {
+			Type *fb = base_type(type_deref(f->type));
+			if (fb->kind == Type_Struct && fb->Struct.polymorphic_parent == dst) {
+				return true;
+			}
+		}
 
 		if (are_types_identical(f->type, dst)) {
 			return level+1;
@@ -4119,7 +4127,7 @@ gb_internal isize check_is_assignable_to_using_subtype(Type *src, Type *dst, isi
 				return level+1;
 			}
 		}
-		isize nested_level = check_is_assignable_to_using_subtype(f->type, dst, level+1, src_is_ptr);
+		isize nested_level = check_is_assignable_to_using_subtype(f->type, dst, level+1, src_is_ptr, allow_polymorphic);
 		if (nested_level > 0) {
 			return nested_level;
 		}
@@ -4135,6 +4143,13 @@ gb_internal bool is_type_subtype_of(Type *src, Type *dst) {
 
 	return 0 < check_is_assignable_to_using_subtype(src, dst, 0, is_type_pointer(src));
 }
+gb_internal bool is_type_subtype_of_and_allow_polymorphic(Type *src, Type *dst) {
+	if (are_types_identical(src, dst)) {
+		return true;
+	}
+
+	return 0 < check_is_assignable_to_using_subtype(src, dst, 0, is_type_pointer(src), true);
+}
 
 
 gb_internal bool has_type_got_objc_class_attribute(Type *t) {