How to extract return type of a class member method ValueDecl?

danielfalbo · 2022-09-09T09:20:39.414Z

I'm playing around with the compiler and I have a ValueDecl whose Type that evaluates to (Square) -> () -> Double when using getInterfaceType(). How do I get Double from that example?

LucianoPAlmeida · 2022-09-10T02:08:32.237Z

You could try this

if(auto fnTy = declVar->getInterfaceType()->getAs<AnyFunctionType>()) {
  if (auto resultFnTy = fnTy->getResult()->getAs<AnyFunctionType>()) { // Get result () -> Double as FunctionType
    auto result = resultFnTy->getResult() // Double
  }
}

Slava_Pestov · 2022-09-10T03:07:34.693Z

If the valueDecl is a FuncDecl, you can also call getResultInterfaceType() to directly get Double there.

danielfalbo · 2022-09-10T10:47:02.218Z

Thank you! It's perfect :)