Databases
StackOverflow2013
Postsdbo
POCan't call method with a pointer to an abstract class in C++
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POCan't call method with a pointer to an abstract class in C++
    primarykey
    data
    text
    <p>In my code I have an unordered map declared like this:</p> <pre><code>std::unordered_map&lt;Collider*, IObject*&gt; map; </code></pre> <p>where <code>IObject</code> is an abstract class that only contains pure virtual functions. After extracting an <code>IObject</code> pointer like this:</p> <pre><code>auto it = map.find(key); </code></pre> <p>where <code>key</code> is a <code>Collider*</code>, I try to access a member function of <code>IObject</code>:</p> <p><code>it-&gt;second-&gt;on_collision();</code> but Intellisense tells me that <code>IObject</code> has no members. Any ideas on what's wrong and possible solutions?</p> <p><strong>EDIT</strong></p> <p>For the curious, here is the class definition of my <code>IObject</code> class:</p> <pre><code>#ifndef IOBJECT_H_ #define IOBJECT_H_ class IObject { public: virtual const char* get_name() const = 0; virtual void set_name(const char* new_name) = 0; virtual void on_collision(const IObject&amp; other) = 0; virtual void update() = 0; }; #endif </code></pre> <p><strong>EDIT2</strong></p> <p>A short SSCCE for y'all, the key I believe is unimportant so I made an int.</p> <pre><code>#include &lt;unordered_map&gt; class IObject { public: virtual void on_collision() = 0; }; class PhysicsController { private: std::unordered_map&lt;int, IObject*&gt; map; public: void check_collisions(); }; void PhysicsController::check_collisions() { int key = 0; auto it = map.find(key); if(it != map.end()) { /* This is the offending line */ it-&gt;second-&gt;on_collision(); } } </code></pre> <p><strong>ANSWER</strong></p> <p>I found out the problem was in fact an issue with forward declarations. Thanks for the help guys</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USmichael60612
    1. USmichael60612
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COIntellisense is often quite the opposite. Does it compile? It could be just fine.
      singulars
      1. POCan't call method with a pointer to an abstract class in C++
      1. USNick Veys
    2. COSidenote: Mapping memory addresses as keys is not exactly common. Are you *sure* you want to do that?
      singulars
      1. POCan't call method with a pointer to an abstract class in C++
      1. USWhozCraig
    3. CO@WhozCraig When it comes down to it, the addresses are just unique numbers so there shouldn't be a problem. Plus insertion and removal from the map are handled by factory create and destroy methods for the Collider class.
      singulars
      1. POCan't call method with a pointer to an abstract class in C++
      1. USmichael60612
 

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