Question

Is it possible to get at run time the type of a generic class that has a variable number of type parameters?

I.e., based on a number, can we get the type of a tuple with this number of elements?

Type type = Type.GetType("System.Tuple<,>");

Answer 1

The way to write that is

Type generic = Type.GetType("System.Tuple`2");

The format of generic types is simple:

"Namespace.ClassName`NumberOfArguments"

` is character 96. (ALT+96).

However i would avoid using strings, it is slower than using typeof, or better, an array lookup.
I would provide a nice static function that is thousand of times faster…

private static readonly Type[] generictupletypes = new Type[]
{
    typeof(Tuple<>),
    typeof(Tuple<,>),
    typeof(Tuple<,,>),
    typeof(Tuple<,,,>),
    typeof(Tuple<,,,,>),
    typeof(Tuple<,,,,,>),
    typeof(Tuple<,,,,,,>),
    typeof(Tuple<,,,,,,,>)
};

public static Type GetGenericTupleType(int argumentsCount)
{
    return generictupletypes[argumentsCount];
}