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    copied!<p>This is definitively possible (see below), but I'm not sure it's worth the trouble... Couldn't you use a simpler approach, perhaps with inheritance and polymorphism?</p> <p>Nevertheless, here is a working solution using Boost.MPL:</p> <pre><code>// MapperRow holds the necessary parsing informations: type of the member, // type of the object, pointer to the appropriate member, parsing function template&lt;typename Type, typename Clazz, Type Clazz::*Member, void (*Parser)(const std::string &amp;, Type &amp;)&gt; struct MapperRow { typedef Type type; typedef Clazz clazz; typedef Type Clazz::*memberType; static const memberType member; typedef void (*parserType)(const std::string &amp;, Type &amp;); static const parserType parser; }; template &lt;typename Type, typename Clazz, Type Clazz::*Member, void (*Parser)(const std::string &amp;, Type &amp;)&gt; const typename MapperRow&lt;Type, Clazz, Member, Parser&gt;::memberType MapperRow&lt;Type, Clazz, Member, Parser&gt;::member = Member; template &lt;typename Type, typename Clazz, Type Clazz::*Member, void (*Parser)(const std::string &amp;, Type &amp;)&gt; const typename MapperRow&lt;Type, Clazz, Member, Parser&gt;::parserType MapperRow&lt;Type, Clazz, Member, Parser&gt;::parser = Parser; // fill iterates over a map key-&gt;MapperRow, trying to find the given key. // if found, it calls the parsing function, otherwise it asserts false (should // probably throw an exception instead) template &lt;typename Clazz, typename First, typename Last&gt; struct fill_impl { static void apply(Clazz &amp;obj, const std::string &amp;key, const std::string &amp;value) { typedef typename mpl::deref&lt;First&gt;::type entry; static const char *curKey = mpl::c_str&lt; typename mpl::first&lt;entry&gt;::type &gt;::value; if (key == curKey) { typedef typename mpl::second&lt;entry&gt;::type Row; Row::parser(value, obj.*Row::member); } else { fill_impl&lt; Clazz, typename mpl::next&lt;First&gt;::type, Last &gt;::apply(obj, key, value); } } }; template &lt;typename Clazz, typename Last&gt; struct fill_impl&lt;Clazz, Last, Last&gt; { static void apply(Clazz &amp;obj, const std::string &amp;key, const std::string &amp;value) { assert(false &amp;&amp; "key not found"); } }; template &lt;typename Map, typename Clazz&gt; void fill(Clazz &amp;obj, const std::string &amp;key, const std::string &amp;value) { fill_impl&lt; Clazz, typename mpl::begin&lt;Map&gt;::type, typename mpl::end&lt;Map&gt;::type &gt;::apply(obj, key, value); } </code></pre> <p>Sample use:</p> <pre><code>template &lt;typename T&gt; void get_value_units(const std::string &amp;str, T &amp;value) { value = T::from_value(boost::lexical_cast&lt;typename T::value_type&gt;(str)); } template &lt;typename T&gt; void get_value_simple(const std::string &amp;str, T &amp;value) { value = boost::lexical_cast&lt;T&gt;(str); } typedef boost::units::quantity&lt;boost::units::si::energy&gt; Energy; typedef boost::units::quantity&lt;boost::units::si::length&gt; Length; struct DeathStar { Length radius; Energy energy; bool operational; int tie_fighters; }; // Could be clearer with MPLLIBS_STRING* typedef mpl::map&lt; mpl::pair&lt; mpl::string&lt;'deat','h_st','ar_r','adiu','s'&gt;, MapperRow&lt; Length , DeathStar, &amp;DeathStar::radius, &amp;get_value_units&lt;Length&gt; &gt; &gt;, mpl::pair&lt; mpl::string&lt;'deat','h_st','ar_e','nerg','y'&gt;, MapperRow&lt; Energy, DeathStar, &amp;DeathStar::energy, &amp;get_value_units&lt;Energy&gt; &gt; &gt;, mpl::pair&lt; mpl::string&lt;'oper','atio','nal'&gt;, MapperRow&lt; bool, DeathStar, &amp;DeathStar::operational, &amp;get_value_simple&lt;bool&gt; &gt; &gt;, mpl::pair&lt; mpl::string&lt;'num_','tie_','figh','ters'&gt;, MapperRow&lt; int, DeathStar, &amp;DeathStar::tie_fighters, &amp;get_value_simple&lt;int&gt; &gt; &gt; &gt; death_star_map; int main() { DeathStar ds; fill&lt;death_star_map&gt;(ds, "death_star_radius", "12"); fill&lt;death_star_map&gt;(ds, "death_star_energy", "34"); fill&lt;death_star_map&gt;(ds, "operational", "1"); fill&lt;death_star_map&gt;(ds, "num_tie_fighters", "56"); std::cout &lt;&lt; "Radius: " &lt;&lt; ds.radius &lt;&lt; '\n'; std::cout &lt;&lt; "Energy: " &lt;&lt; ds.energy &lt;&lt; '\n'; std::cout &lt;&lt; "Operational: " &lt;&lt; std::boolalpha &lt;&lt; ds.operational &lt;&lt; '\n'; std::cout &lt;&lt; "Tie fighters: " &lt;&lt; ds.tie_fighters &lt;&lt; '\n'; } </code></pre> <p>* <a href="http://abel.web.elte.hu/mpllibs/metaparse/MPLLIBS_STRING.html" rel="nofollow">MPLLIBS_STRING</a></p>
 

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