[/ Copyright (c) 2019-2025 Ruben Perez Hidalgo (rubenperez038 at gmail dot com) Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) ] [section:boost__mysql__WritableFieldTuple WritableField and WritableFieldTuple concepts] A type is a `WritableField` if it can be used to represent a statement parameter value to be sent to the server. A type `T` satisfies `WritableField` if it is [link mysql.prepared_statements.writable_field_reference any of the types listed in this table]. More types may be added in future releases. A type `T` is a `WritableFieldTuple` if it's a `std::tuple` specialization, or a reference to one, and all element types fulfill `WritableField`, or are (possibly cv-qualified) references to `WritableField` types. Empty tuples satisfy `WritableFieldTuple`. [endsect]