RoslynDifference1.cs

using System;

public class C {
    public void M() {
        dynamic n;
        dynamic c = "";

        //
        // Roslyn marks use of 'n' in 'n > 0' as possibly unassigned;
        // compiles fine with csc.exe in VS2013.
        //
        bool b = c != null &&
                 F(c, out n) &&
                 n > 0;
    }
    
    private static bool F(object x, out object value) {
        value = 42;
        return true;
    }
}