CODEWITHSUNDEEP
c++c++11
user1319951
user1319951

Reputation: 505

Passing a char array by value

I have problem with passing a char array by value to a priority_queue. I want to pass a unique value to the constructor, but I can only assign the type in the priority queue to char*. This causes a problem since the value passed changes through each iteration in the algorithm and then all the values in the priority queue (since every element is a pointer to task). Here is a code sample:

 char task[100];
 char priority;
 pair<int, char*> temp;
 priority_queue< int, vector<pair<int, char*>>, compare> queue;
 printf("Define a priority and a task to be done (exit by pressing CTRL-D):\n\n");
 do {
    priority=getchar();
    if(isdigit(priority)){
      scanf("%s", task);
      temp=make_pair(atoi(&priority), task); //I want to pass by value here not by reference, is there any solution to this?
      queue.push(temp);
      printf("%i %s\n", temp.first, temp.second);
    }
 } while(priority != EOF);

Is there any way that I can assign a unique string to every element of the priority queue?

Upvotes: 1

Views: 1008

Answers (2)

MAnyKey
MAnyKey

Reputation: 567

As comment to question suggests you can wrap char [100] and int to new type (since pair<> gives poor abstraction). Another option is to use std::string, std::vector<char>, std::array<char, 100> instead of char[100].

PS: call to atoi(&priority) might fall because atoi expects null-terminated C-string, not a pointer to single character.

Upvotes: 2

Useless
Useless

Reputation: 67743

You could use something like std::array<char,100> I guess, but your current vector type requires a dynamically allocated string.

Do you want to force every element of your vector to be more than 100 bytes, however long the string?

Upvotes: 0

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