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## Macro BOOST_VARIANT_ENUM_PARAMS

BOOST_VARIANT_ENUM_PARAMS — Enumerate parameters for use with `variant`.

## Synopsis

    // In header: <boost/variant/variant_fwd.hpp>

    BOOST_VARIANT_ENUM_PARAMS(param)

## Description

When variadic templates are available and `BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES` is not defined, expands to variadic template list in the following manner: ``

                BOOST_VARIANT_ENUM_PARAMS(T)                    => T0, TN...
                BOOST_VARIANT_ENUM_PARAMS(class T)              => class T0, class... TN
                BOOST_VARIANT_ENUM_PARAMS(class Something)      => class Something0, class... SomethingN
                BOOST_VARIANT_ENUM_PARAMS(typename Something)   => typename Something0, typename... SomethingN
                BOOST_VARIANT_ENUM_PARAMS(Something)            => Something0, SomethingN...
                BOOST_VARIANT_ENUM_PARAMS(Something)            => Something0, SomethingN...

Otherwise expands to a comma-separated sequence of length `BOOST_VARIANT_LIMIT_TYPES`, where each element in the sequence consists of the concatenation of param with its zero-based index into the sequence. That is, `param ## 0, param ## 1, ..., param ## BOOST_VARIANT_LIMIT_TYPES - 1`.

Rationale: This macro greatly simplifies for the user the process of declaring `variant` types in function templates or explicit partial specializations of class templates, as shown in the tutorial.