General C++ Programming - C++ Forum - January 2016 (Page 11)

Cannot initialize "BaseClass **" with an rvalue of type "DerivedClass **"

Here's my code: Bird *polly = new Bird(); Animal **pollyPtr = &bird; The previous line is giving me the error in the title. Please tell me how I fi this. :)

[2 replies] Last: > Cannot initialize "BaseClass **" with an rvalue of type "DerivedClas... (by JLBorges)

by Kubani

Defining operators for vectors of templates

I'm reading Programming Principles and Practice Using C++ first edition first printing book. This book is really hard for beginners but I have studied it unti...

[15 replies] Last: Yes and what is question for me is that why the author (the creator o... (by cire)

by omega4relay

how to insert pair values in a map into a normal map

So if I have a map m1 that has pairs of <string,pair<string,int>>, how do I 'extract' the value of m1's pairs and put them into a new map m2 so that I have norm...

[1 reply] : Maybe something like this: for (std::map<string,pair<string,int>>... (by Chervil)

by niko79542

Is it OK to make node struct public within stack class?

I wrote a stack data structure. It is a series of nodes . Each node has a value, and a pointer to its parent node...and child node. Is it bad to make variabl...

[5 replies] Last: Yes Doug, all of your assumptions about my stack were correct. Much s... (by niko79542)

by gedamial

Question about the rand() function

Hello. I want to make a program that, given the minimum value and the maximum value, generates a random number within that range. I made that with this co...

[13 replies] Last: It returns the rest of the division btween rand() and what comes after... (by gedamial)

by rabster

Linked List questions

So far I've made a linked list with relatively little help, which is why I now need it. My linked list "works" but to me doesn't look very efficient. For instan...

[2 replies] Last: Well I'm using the pointers for the list. And yeah, now that I think a... (by rabster)

by saramarikar

C== chat application

hi. i have been doing a c++ client server chat application with exceptions . but when i run the server code the system breaks. how can i fix it? here is the c...

[5 replies] Last: is this server code ok? #include <winsock2.h> #include <ws2tcpip.h> ... (by saramarikar)

by technologist

dereferencing question (1,2)

Leading up to the question, this example shows simple dereference: value foo = 500; int * n_ptr = &foo; cout<<*n_ptr; 500 Below, what does (*n_ptr) der...

[22 replies] Last: but also a struct as well. The struct having public member access by... (by MikeyBoy)

by dinesh98

problem regarding files

i am working on my c++ school project. i have a problem in that. i have a class with 3 char data members. while writing to a file, the first 2 are written and t...

[2 replies] Last: The clairvoyants are off duty now. Can you show the code so that ordin... (by Thomas1965)

by mike9407

static variables

how to use static variables?what is the point of using it?

[3 replies] Last: Storage class specifiers http://en.cppreference.com/w/cpp/language/sto... (by closed account E0p9LyTq)

by YvngSavage

Help Debugging (1,2)

#include <iostream> using namespace std; int main() { char response; cout<<"You enter a dark hallway deep under ground..."<<endl; cout<<"///...

[23 replies] Last: Yes, I had a sick day from school and I got bored and had the idea lol (by YvngSavage)

by kam hagh

how to make my function accept both const char* and string

I have a function in my class: Serial::Serial(std::string* portname) { file.open(portname->c_str()); } do I have to write this function 2 times to m...

[7 replies] Last: With modern C++, with move semantics, passing a string [by value] doe... (by Peter87)

by abc1

Sorting

Which of the following sorting algorithm is of divide and conquer type? A) Bubble sort B) lnsertion sort C) Quick sort D) Merge sort Please help......

[4 replies] Last: Merge Sorting algorithm and Quick sort algorithm are known as divide a... (by GrShultz)

by ajaythk

how to look for the index of a vector in an array

int D ={ {1, 0, 0}, {0, 1, 0}, {0, 0, 1}, {0, 0, 0}, {0, 0, 0},...

[4 replies] Last: You could use a bool variable as a flag. Set it to true at the sta... (by Chervil)

by Steve Valentain

Minimum processing cost!!

Hello everyone!! I need some help if possible with my problem given to me from my teacher.I will describe it here: Assume that processing a list of items costs...

[4 replies] Last: I used f variable to be assigned to the list2 array,so it can increm... (by cire)

by Gyiove

Hyperbolic Secant in c++

Hello everyone! Does anyone have a hyperbolic secant function? I found this: http://mathworld.wolfram.com/HyperbolicSecant.html But i don't understand...

[5 replies] Last: Hill representing momentum of how number changes Even if sech(1) ~= 1... (by helios)

by DubKing

How do i get more dubs? (Blackjack code)

#include <iostream> #include <ctime> #include <cmath> #include <cstdlib> #include <stdio.h> #include <stdlib.h> #include <windows.h> #define _WIN32_WINNT...

[1 reply] : This is very hard to read. Please Remember to put code tags. I really ... (by Hirokachi)

by TarikNeaj

loop help?

I cannot attach a screen shot but this code compiles. Ehh no it does not at all. It would be much easier if you actually provided a piece of code that compil...

[5 replies] Last: so could you. Are you going to continue to waste my time or are you g... (by MikeyBoy)

by mike9407

need help

i need help on a guy who is nice and friendly

[1 reply] : So what's the problem? Is the guy not compiling properly? (by Michael5)

by CruxHaloine

Trying to read a specific line of text from a file

I've got a dump file from a mathematical problem that records all tried solutions to a specific formula. Since I will be starting and stopping my program multip...

[2 replies] Last: Here is a little example to read the last 26 chars from a file. #inc... (by Thomas1965)

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General C++ Programming - January 2016 (Page 11)