Re: GHashTable and const

[Alberto Mardegan <mardy users sourceforge net>]

ext Brian J. Tarricone wrote:
> Now, that's for C.  For C++ passing a const pointer to a function 
> expecting a non-const pointer actually a hard *error*[1].  So the API 
> couldn't be changed in this way without likely breaking any C++ 
> application that uses these glib data structures.

Yes, but this is not our case: by introducing const in some of the API 
parameters we don't restrict their usage: you can always pass them a 
non-const variable in C++ too, right?

> Personally, I mainly see it as a hint to the programmer so I can tell at 
> a glance that the function doesn't modify the parameter (const) or may 
> modify the parameter (non-const).  I'd agree that any speed benefits are 
> probably very small (if nonexistent), so the burden would be on someone 
> to benchmark to prove otherwise.  If the API were being designed from 
> scratch, I'd say sure, use const as a semantic identifier.  But at this 
> point it's just too late to do it without breaking C++ programs that use 
> glib.

I might be ignorant on C++, but I don't see why this would break 
anything. I'm not saying that g_hash_table_new() must return a const 
GHashTable, but I'd like to be able to pass a const GHashTable to a 
function like g_hash_table_size() without warnings or casts.

Ciao,
  Alberto

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