Id

            pub const Id = enum(u5) {
                unnamed_test,
                @"test",
                decltest,
                @"comptime",

                const_simple,
                const_typed,
                @"const",
                pub_const_simple,
                pub_const_typed,
                pub_const,

                extern_const_simple,
                extern_const,
                pub_extern_const_simple,
                pub_extern_const,

                export_const,
                pub_export_const,

                var_simple,
                @"var",
                var_threadlocal,
                pub_var_simple,
                pub_var,
                pub_var_threadlocal,

                extern_var,
                extern_var_threadlocal,
                pub_extern_var,
                pub_extern_var_threadlocal,

                export_var,
                export_var_threadlocal,
                pub_export_var,
                pub_export_var_threadlocal,

                pub fn hasName(id: Id) bool {
                    return switch (id) {
                        .unnamed_test,
                        .@"comptime",
                        => false,
                        else => true,
                    };
                }

                pub fn hasLibName(id: Id) bool {
                    return switch (id) {
                        .extern_const,
                        .pub_extern_const,
                        .extern_var,
                        .extern_var_threadlocal,
                        .pub_extern_var,
                        .pub_extern_var_threadlocal,
                        => true,
                        else => false,
                    };
                }

                pub fn hasTypeBody(id: Id) bool {
                    return switch (id) {
                        .unnamed_test,
                        .@"test",
                        .decltest,
                        .@"comptime",
                        => false, // these constructs are untyped
                        .const_simple,
                        .pub_const_simple,
                        .var_simple,
                        .pub_var_simple,
                        => false, // these reprs omit type bodies
                        else => true,
                    };
                }

                pub fn hasValueBody(id: Id) bool {
                    return switch (id) {
                        .extern_const_simple,
                        .extern_const,
                        .pub_extern_const_simple,
                        .pub_extern_const,
                        .extern_var,
                        .extern_var_threadlocal,
                        .pub_extern_var,
                        .pub_extern_var_threadlocal,
                        => false, // externs do not have values
                        else => true,
                    };
                }

                pub fn hasSpecialBodies(id: Id) bool {
                    return switch (id) {
                        .unnamed_test,
                        .@"test",
                        .decltest,
                        .@"comptime",
                        => false, // these constructs are untyped
                        .const_simple,
                        .const_typed,
                        .pub_const_simple,
                        .pub_const_typed,
                        .extern_const_simple,
                        .pub_extern_const_simple,
                        .var_simple,
                        .pub_var_simple,
                        => false, // these reprs omit special bodies
                        else => true,
                    };
                }

                pub fn linkage(id: Id) Declaration.Unwrapped.Linkage {
                    return switch (id) {
                        .extern_const_simple,
                        .extern_const,
                        .pub_extern_const_simple,
                        .pub_extern_const,
                        .extern_var,
                        .extern_var_threadlocal,
                        .pub_extern_var,
                        .pub_extern_var_threadlocal,
                        => .@"extern",
                        .export_const,
                        .pub_export_const,
                        .export_var,
                        .export_var_threadlocal,
                        .pub_export_var,
                        .pub_export_var_threadlocal,
                        => .@"export",
                        else => .normal,
                    };
                }

                pub fn kind(id: Id) Declaration.Unwrapped.Kind {
                    return switch (id) {
                        .unnamed_test => .unnamed_test,
                        .@"test" => .@"test",
                        .decltest => .decltest,
                        .@"comptime" => .@"comptime",
                        .const_simple,
                        .const_typed,
                        .@"const",
                        .pub_const_simple,
                        .pub_const_typed,
                        .pub_const,
                        .extern_const_simple,
                        .extern_const,
                        .pub_extern_const_simple,
                        .pub_extern_const,
                        .export_const,
                        .pub_export_const,
                        => .@"const",
                        .var_simple,
                        .@"var",
                        .var_threadlocal,
                        .pub_var_simple,
                        .pub_var,
                        .pub_var_threadlocal,
                        .extern_var,
                        .extern_var_threadlocal,
                        .pub_extern_var,
                        .pub_extern_var_threadlocal,
                        .export_var,
                        .export_var_threadlocal,
                        .pub_export_var,
                        .pub_export_var_threadlocal,
                        => .@"var",
                    };
                }

                pub fn isPub(id: Id) bool {
                    return switch (id) {
                        .pub_const_simple,
                        .pub_const_typed,
                        .pub_const,
                        .pub_extern_const_simple,
                        .pub_extern_const,
                        .pub_export_const,
                        .pub_var_simple,
                        .pub_var,
                        .pub_var_threadlocal,
                        .pub_extern_var,
                        .pub_extern_var_threadlocal,
                        .pub_export_var,
                        .pub_export_var_threadlocal,
                        => true,
                        else => false,
                    };
                }

                pub fn isThreadlocal(id: Id) bool {
                    return switch (id) {
                        .var_threadlocal,
                        .pub_var_threadlocal,
                        .extern_var_threadlocal,
                        .pub_extern_var_threadlocal,
                        .export_var_threadlocal,
                        .pub_export_var_threadlocal,
                        => true,
                        else => false,
                    };
                }
            }