The return type of operator True or False must be bool
User-defined true and false operators must have a return type of bool.
The following sample generates CS0215:
class MyClass { public static int operator true (MyClass MyInt) { // CS0215 // try the following line instead // public static bool operator true (MyClass MyInt) { return true; } public static int operator false (MyClass MyInt) { // CS0215 // try the following line instead // public static bool operator false (MyClass MyInt) { return true; } public static void Main() { } }