Hi Christian, ________________________________________ De: boost-bounces@lists.boost.org [boost-bounces@lists.boost.org] En nombre de Christian Larsen [contact@dword.dk] Enviado el: martes, 02 de septiembre de 2008 21:55 Para: boost@lists.boost.org Asunto: Re: [boost] [flyweight] post-review version available
JOAQUIN M. LOPEZ MUÑOZ skrev:
I've tried to address most of the suggestions and comments raised during the review. The two most important changes are: 1. Alberto Barbati's insightful review has led to the introduction of so-called key-value flyweights (http://tinyurl.com/5mnwjp ). [...]
I just read the start of the tutorial, and I like what I see. I haven't tried using the library yet, though. But I have a question regarding the last assignment in the "Key extractors" section.[...]
struct texture_filename_extractor {...}; flyweight<key_value<std::string,texture, texture_filename_extractor> > fw; ... fw=texture("sand.texture"); // OK now
I get it that this is to show the need for key extractors, but isn't it possible to also assign without creating already existing textures?[...] Wouldn't the optimal way to perform this assignment be something like:
typedef flyweight<key_value<std::string,texture, texture_filename_extractor> > texture_fw; texture_fw fw; ... fw=texture_fw("sand.texture"); // No unnecessary construction?
Yep, you're absolutely correct. The suboptimal assignment 'fw= texture("sand.texture")' is used just to show where key extractors are needed.
If this is the case, I think it would improve the documentation if a note was added after the example that this is the best way to do an assignment from a "new" texture. Please correct me if I'm wrong.
Yes, the docs can be misleading here. I'll either clarify the point in the docs or else rewrite the snippet in a way that makes it impossible to optimize the expression, something like void foo(const texture& x) { flyweight<key_value<std::string,texture> > fw(x); } Thanks for your feedback, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo