Databases
StackOverflow2013
Postsdbo
POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
    primarykey
    data
    text
    <p>Say I have a struct that has a bunch of member variables. I want to write a function that will set the value of any of those members (along with a few other things, but I think that is beyond the scope of the question). Something like (but obviously not) this:</p> <pre><code>struct A { A() { /* do stuff */ } bool a1; bool a2; bool a3; void set_member(???); bool get_member(???); }; A a; a.set_member(a1, true); bool value = a.get_member(a1); </code></pre> <p>Now, my first thought is to use an array instead of a bunch of named variables. I would like to do that, but this is code that I would not like to touch in that way if I can help it (it is legacy). It has a constructor so I'm not even sure if it will maintain it's binary serializablility characteristics since it is not a POD. Even if it were a POD, I'm still not convinced as <code>a1</code>, <code>a2</code> and <code>a3</code> can have different alignment than that on an array of <code>bool</code>s.</p> <p>So, going back to the original question, is there a way of doing this? Perhaps with some template trick that I'm not aware of yet?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USXeo
    1. USAdrian
    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. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
      1. This table or related slice is empty.
      1. VTDownMod
    1. COall members are booleans?
      singulars
      1. POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
      1. UShasan
    2. COIs there any reason you couldn't write individual set and get methods for each variable? Is there something that you want to do that requires you do have a single get and set method? Unless you are willing to return something like boost::any, or all of your member variables are of the same type, you're going to need more than one get method.
      singulars
      1. POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
      1. USrazeh
    3. COWhy don't you use switch operator?
      singulars
      1. POHow can I write a function to modify a struct's member value without knowing the member's name ahead of time?
      1. USklm123
 

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