Hamish Mackenzie wrote:
On Wed, 2005-10-19 at 09:16 -0400, David Abrahams wrote:
Do you think the "fill" example would be useful to fill missing values in vector< OptionalPointee >?
Sorry, I don't understand.
Sorry I was in a hurry and didn't describe what I was thinking better. Here is the example from the other email.
I get your point. You're looking for general usages of the Nullable concept (I won't call it OptionalPointee anymore). I like that.
template< typename OptionalPointee, typename Value_Type > Optional_Pointee fill( Optional_Pointee x, Value_Type & default_value ) { if( x == none ) { x = &default_value; // Does this work with optionals? }
return x; }
No, that doesn't work with optional<>. Furthermore, this is a bad example. In the usage example below, 'x1' would end up with several pointers to the 'default_value' object, while 'x2' would end up with several distinct copies of 'default_value' wrapped inside optional<>. But I like the idea of looking for usefull usages of the Nullable concept. -- Fernando Cacciola SciSoft http://fcacciola.50webs.com/