Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Convert your container to use <code>shared_ptr</code> as the member:</p> <pre><code>#include &lt;boost/ptr_container/ptr_vector.hpp&gt; #include &lt;boost/shared_ptr.hpp&gt; #include &lt;vector&gt; class Object { public: int m_Id; Object(int id) : m_Id(id) { } }; class ObjectManager { private: typedef boost::shared_ptr&lt;Object&gt; ObjectPtr; typedef std::vector&lt;ObjectPtr&gt; ObjectVectorPtr; typedef ObjectVectorPtr::iterator ObjectIt; ObjectVectorPtr vector_; void AddObject(ObjectPtr&amp; obj) { vector_.push_back(obj); } ObjectPtr FindObject(int id) { for (ObjectIt it = vector_.begin(); it != vector_.end(); ++it) { if (it-&gt;get()-&gt;m_Id == id) { // Found the object - return a shared_ptr reference to it return ObjectPtr(*it); } } // We could not find anything. return ObjectPtr(); } }; </code></pre> <p>btw - prefer <code>++it</code> vs <code>it++</code> to avoid extra construction, and don't use matching like this if the container gets large - switch to <code>std::map&lt;int, ObjectPtr&gt;</code> with <code>m_id</code> as the key, or <a href="http://msdn.microsoft.com/en-us/library/e8wh7665(VS.80).aspx" rel="nofollow noreferrer">std::set</a> with suitably-defined <code>less</code> function.</p> <p>If I was being super-pedantic I would suggest replacing your find loop with a call to <a href="http://msdn.microsoft.com/en-us/library/wkwky1wa(v=VS.90).aspx" rel="nofollow noreferrer">std::find_if</a>, with a predicate that matches on <code>Object::m_id</code>...</p>
    singulars
    1. This table or related slice is empty.
    1. POHow to retrieve a reference from a boost ptr_vector?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USSteve Townsend
    1. USSteve Townsend
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POHow to retrieve a reference from a boost ptr_vector?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COAhh, thanks Steve! Also, if you don't mind answering, when you said "don't use matching like this if the container gets large," are you referring to performance issues?
      singulars
      1. PO
      1. USjbaez
    2. CO@jbaez : yes this is perf-related - matching like this will be O(n) - searching map (binary tree) is O(log n)
      singulars
      1. PO
      1. USSteve Townsend
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload