Why is Func<T> ambiguous with Func<IEnumerable<T>>?
- by Matt Hamilton
This one's got me flummoxed, so I thought I'd ask here in the hope that a C# guru can explain it to me.
Why does this code generate an error?
class Program
{
static void Main(string[] args)
{
Foo(X); // the error is on this line
}
static String X() { return "Test"; }
static void Foo(Func<IEnumerable<String>> x) { }
static void Foo(Func<String> x) { }
}
The error in question:
Error
1
The call is ambiguous between the following methods or properties:
'ConsoleApplication1.Program.Foo(System.Func<System.Collections.Generic.IEnumerable<string>>)' and 'ConsoleApplication1.Program.Foo(System.Func<string>)'
C:\Users\mabster\AppData\Local\Temporary Projects\ConsoleApplication1\Program.cs
12
13
ConsoleApplication1
It doesn't matter what type I use - if you replace the "String" declarations with "int" in that code you'll get the same sort of error. It's like the compiler can't tell the difference between Func<T> and Func<IEnumerable<T>>.
Can someone shed some light on this?
