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[Important] Important

This module is only available with C++ 14 and above.

#include <boost/phoenix/stl/tuple.hpp>

The tuple module provides a lazy version of std::get called get_. In addition to std::tuple (and std::pair) the get_<int> syntax can also be used with std::array, and the get_<type> syntax with std::variant. An example is below:

// using namespace boost::phoenix;
auto get_first_item = get_<0>(placeholders::arg1);
auto get_double = get_<double>(placeholders::arg1);
[Tip] Tip

Other types may also be supported if get is implemented for them.

It also provides additional placeholders uarg1..uargN which unpack the first argument. These are defined as:

namespace placeholders {
auto uarg1 = boost::phoenix::get_<0>(arg1);
auto uarg2 = boost::phoenix::get_<1>(arg1);
auto uarg10 = boost::phoenix::get_<9>(arg1);