My Kingdom For ...

[Christopher Wright]

Ary Borenszweig wrote:
> Janice Caron escribió:
>> On 21/02/2008, Michiel Helvensteijn <nomail at please.com> wrote:
>>> It's silly that 'in' does not return a bool.
>>
>> Huh? But I don't want it to return a bool. If it retured a bool, I
>> wouldn't be able to do
>>
>>     auto p = key in aa;
>>     if (p is null)
>>     {
>>         /* do something */
>>     }
>>     else
>>     {
>>         return *p;
>>     }
>>
>> Without that ability, you'd have to do a double-lookup!
> 
> I think the best solution is the one in .Net:
> 
> object value;
> if (aa.TryGetValue(key, out value)) {
>   // Key found, value may be null
> } else {
>   // Key not found
> }

That would be better if the language allowed:
// value not defined
if (aa.TryGetValue(key, out object value))
{
   // ok, now I can use value
}
else
{
   // Key not found
}