c# - Switch on Type with Dictionary on Func and async / await -

i'm trying write piece of code doesn't compile (stuff deleted/simplifiied):

private async task<patientchartdata> getdomainlistingsummarymeta<t>(string phn)      t : patientchartbase, new() {     var getlistingsummarytypeswitch = new dictionary<type, func<????>> {         { typeof(documents), async () => await this.getdocuments(phn) },         { typeof(encounters), async () => await this.getencounters(phn) },         { typeof(labs), async () => await this.getlabs(phn) },     };     task t = new task(async () =>     {         // code without switch, e.g.         // await this.getdocuments(phn);          // type switch, want this:         await getlistingsummarytypeswitch(typeof(t))();     });     t.start(); // notice, not waiting task complete } 

getdocuments returns task, getencounters returns task, etc. however, in current design, don't care response call them in background thread have side-effects (e.g. putting them in database/cache, etc.) please ignore design issues being background threads.

my question syntax on how make work.

you want use type indexer not argument?

        await getlistingsummarytypeswitch[typeof(t)](); 

regarding func<???>: must return awaitable, otherwise cannot use await in front of switch. use func<task> or generic func<task<resulttype>>.

i won't discuss other flaws (like wrapping in task) discussed in comments-section of question, because said simplified it.