Checking what type is passed into a generic method

Question

How do I check what is the type passed as type parameter for a generic method?

foo<T>() {
   // What type is T?
   // I want to able to do something like,
   // if T is String do something, if T is int do something else.
}

Answer 1

You can use the equality (==) operator in the latest Dart SDK versions:

foo<T>() {
  if (T == String) {

  } else if (T == int) {

  }
}

One thing that's not trivial to do is inspect generic types, however:

foo<T>() {
  // Invalid syntax.
  if (T == List<String>) {}
}

In that case, you'll want more specialized methods:

fooOfT<T>(List<T> list) {
  if (T == String) {

  }
}