gistfile1.cs

bool CanConvert(Type source, Type destination)
{
    try
    {
        Expression.Convert(Expression.Default(source), destination);
        return true;
    }
    catch (InvalidOperationException)
    {
        return false;
    }
}

bool CanCast(Type s, Type d)
{
    if (!d.IsAssignableFrom(s) && s.IsAssignableFrom(d))
    {
        return false;
    }

    try
    {
        Expression.Convert(Expression.Default(s), d);
        return true;
    }
    catch (InvalidOperationException)
    {
        return false;
    }
}