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Vector of pointers: some clarification needed


Vector of pointers: some clarification needed

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Vector of pointers: some clarification needed
Tag : cpp , By : Santhanam
Date : December 01 2020, 04:55 PM


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rails 3: clarification needed on which controllers are needed for HABTM relationships


Tag : ruby-on-rails , By : OllieDoodle
Date : March 29 2020, 07:55 AM
this will help I think that one way to do it could be the following:
I would accept the event to have the user as a nested resource this way:
class Event < ActiveRecord::Base
    has_many :users
    accepts_nested_attributes_for :events 
end
class ApplicationController < ActionController::Base
  def add_user_to_event
    @event = Event.find(params[:event])
    @user = User.find(params[:user])
    @event.users << @user
    @event.save
  end
end

Some clarification needed in the struct pointers


Tag : c , By : Diego
Date : March 29 2020, 07:55 AM
With these it helps The problem here is that the "->" operator is binding more tightly than the "*" operator. So your first statement:
// what you have written
*root->link;
// what you're getting - bad
*(root->link);
// what you want - good
(*root)->link;

On C++ pointers and references, clarification needed


Tag : cpp , By : Jesse
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further
void foo (int &something) // Will accept an address of something
void foo (something); // "something" must be a variable

(C++) Clarification needed about accessing derived functions from a vector of pointers


Tag : cpp , By : user161380
Date : March 29 2020, 07:55 AM
Hope this helps It is hard to follow what exactly do you mean, but I think you refer to automatic allocation getting destroyed. Something among the lines of:
// WARNING: incorrect code
std::vector<base*> v;
for (int i = 0; i < 10; i++) {
  Derived d;
  v.push_back(&d);
}

v[0]->foo();
// WARNING: incorrect code
std::vector<base*> v;
for (int i = 0; i < 10; i++) {
  Derived* d = new Derived();
  v.push_back(d);
  delete d;
}

v[0]->foo();

Pass vector of pointers by reference and replace a vector of void* pointers


Tag : cpp , By : jaime
Date : March 29 2020, 07:55 AM
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