internal TResult Invoke <TResult>(object instance, MethodId method, Func <TInterface, TResult> f)
{
// If the last n - 1 calls are to the same method,
// call the n-th implementation.
var instanceAndMethod = new InstanceAndMethod(instance, method);
int n = _calls.Count;
int index = 0;
while ((n - index > 0) && _calls[n - index - 1].Equals(instanceAndMethod))
{
index++;
}
if (index == _implementations.Length)
{
throw new InvalidOperationException();
}
var item = _implementations[index];
_calls.Push(instanceAndMethod);
try
{
return(f(item));
}
finally
{
_calls.Pop();
}
}
internal bool Equals(InstanceAndMethod other)
{
return(Instance == other.Instance && Method == other.Method);
}
