BOOST_PP_TUPLE_ELEM

The BOOST_PP_TUPLE_ELEM macro extracts an element from a tuple.

#### Usage

BOOST_PP_TUPLE_ELEM(i, tuple) (v)
or
BOOST_PP_TUPLE_ELEM(size, i, tuple) (v)

#### Arguments

size
  The size of the tuple. The size is ignored.
i
  The zero-based index into the tuple of the element to be extracted. Valid values range from 0 to size - 1.
tuple
  The tuple from which an element is to be extracted.

#### Remarks

You can invoke the variadic macro as BOOST_PP_TUPLE_ELEM(i,tuple), or BOOST_PP_TUPLE_ELEM(size,i,tuple) for backward compatibility.

#### See Also

- BOOST_PP_LIMIT_TUPLE

#### Requirements

Header: <boost/preprocessor/tuple/elem.hpp>

#### Sample Code

    #include <boost/preprocessor/tuple/elem.hpp>

    #define TUPLE (a, b, c, d)

    BOOST_PP_TUPLE_ELEM(0, TUPLE) // expands to a in the variadic version
    BOOST_PP_TUPLE_ELEM(3, TUPLE) // expands to d in the variadic version

© Copyright Housemarque Oy 2002
© Copyright Paul Mensonides 2002
© Copyright Edward Diener 2011,2013,2020

Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at www.boost.org/LICENSE_1_0.txt)