What is the preferred method for testing the existence of a key in an associative array?

[Jacob Carlborg]

On 2013-09-13 16:17, Orvid King wrote:

> Well, I usually do it as:
>
> int[string] someCache;
>
> int getValue(string key)
> {
>      if (auto val = key in someCache)
>          return *val;
>      return someCache[key] = -3;
> }

That doesn't work with generic code. I mean, -3 can be a legal value. 
There are many types that doesn't have an invalid value, like pointers do.

-- 
/Jacob Carlborg