Dynamic function typings based on string params passed

[wclr]

Probably this is an issue of dynamic typing, didn't find exact here in the issues (probably you will point to).

Is it possible to do typing and achieve types flow of such thing:

function getProp(prop: string, obj: any) {
  return obj[prop]
}  

let obj: { id: number } = { id: 1 }

getProp('id', obj). // there should flow number type

[gcnew]

Rumor has it that it was once considered in a distant whimsical land, where unicorns walk freely under rainbows and mighty wombats support the sky. It is, however, deemed intractable for the feeble human beings.

Use #1295 as a starting point, see #10425.

[wclr]

@gcnew thanks for pointing on that

[mhegazy]

indeed duplicate.