template<template<class> class use, class Option, typename field, typename sel, typename vec, typename tag, typename... tags>
tk::grm::action<insert_option<use, Option, field, sel, vec, tag, tags...>> struct

Convert and insert option value to map at position given by tags.

This struct and its apply function are used as a functor-like wrapper for converting and inserting an option in a std::map in the grammar stack. An option is an object deriving from tk::Toggle. See, e.g., walker::ctr::DiffEq for an example specialization of tk::Toggle to see how an option is created from tk::Toggle.