Question

Does anyone know or care to speculate why implicit typing is limited to local variables?

var thingy = new Foo();

But why not…

var getFoo() {
    return new Foo(); 
}

Answer 1

Eric Lippert did an entire blog post on the subject.

• https://learn.microsoft.com/en-us/archive/blogs/ericlippert/why-no-var-on-fields

In summary, the main problem is that it would have required a major re-architecture of the C# compiler to do so. Declarations are currently processed in a single pass manner. This would require multiple passes because of the ability to form cycles between inferred variables. VB.NET has roughly the same problem.