Been away from c++ for a few months now (apart from answering a few questions on this site). I was trying to see if I could do a simple program using just my memory that involved unique_ptr's, but getting an error:
"attempting to reference a deleted function". I thought that by getting a reference to my pointer would not invoke a copy constructor but i'm clearly wrong.
For a project we are given a file with a couple of thousand lines of values, each line having 9 different numbers.
I want to create a for/while loop that, for each loop, stores the 8th and 9th integer of a line as a variable so that I can do some calculations with them. The loop would then move onto the next line, store the 8th and 9th numbers of that line as the same variable, so that I can do the same calculation to it, ending when I've run out of lines.
My problem is less to do with reading the file, I'm just confused how I'd tell it to take only the 8th and 9th value from each line.
Is there any way to set a "lock" on certain couts from system ("cls"). You can this with const to "lock" a variable to a certain value so I am wondering if that is true for couts from system ("cls"). This would make my program much simpler to write.
Say I have an object and 10 pointers to it in several other objects of varying class types. if the object gets deleted, those pointers have to be set to null. normally I would interconnect the object's class with the classes which have pointers to it so that it can notify them it is being deleted, and they can set their pointers to null. but this also has the burden that the classes must also notify the object when THEY are deleted since the object will need a pointer to them as well. That way the object doesn't call dereference a dangling pointer when it destructs and attempts to notify the others.
Auto pointers and shared pointers are not what I'm looking for - auto pointers delete their object when they destruct, and shared pointers do the same when no more shared pointers are pointing to it. What I'm looking for is a slick method for setting all pointers to an object to null when the object destructs.
I have a small questions in the behavior of Structure, I have declare a structure with 10 components. Some of the components in the structure has already their value but when I use
The structure components in a function DLL function those value I set previously has been deleted or empty. I don't know what is the problem...
1. I want to make a file in the program directory that can't be deleted by user out of the program make that file.for example if I make a file named "123.xyz" by the program named "text.exe" and then exit test.exe ,if I tried to delete the file 123.xyz I faced the error and I could not do it but by the test.exe program that make that file.
2. I heard about a function called "Parbegin()".any way i want to know is there any possible way to run two or more functions of a file.c together,like the parbegin function did an do in OS?
I get the error at the line "ptr1 = new node;" I tried putting a default constructor for my node struct and that fixed the problem but a new problem arises. It states that i have a linker error after i compile it with a default constructor.
I'm making a program that's essentially a Text-Based Fire Emblem game; it runs calculations and rolls dice and has all sorts of Goodies. However, I have hit a block to the tune of
#ifndef ITEM_H #define ITEM_H class Item {
[Code]....
Up Until I called up a Sword object, it worked fine. But when I compiled it, I got an Undefined Reference to Item::Item() error in Line 8 of Weapon.cpp.
Everything seems to be in order and I know my code still has mistakes. I'm just trying to get it to compile and it won't allow it. I've narrowed it down to when I call the functions in main but beyond that I have no clue.
#include <iostream> #include <cstring> using namespace std; void getSize(int num); void getSpace(int num, int ptr); void inputData(); void printData(); void destroy(); const int BIG_NUMBER = 100;
//pa4.cpp wirtten by Syd Frederick #include<iostream> #include<string> #include<fstream>
[Code].....
When compiling I'm getting a strange error that says :
/tmp/ccdt0Bf9.o: In function `main': pa4.cpp:(.text+0x1c): undefined reference to `synopsis()' pa4.cpp:(.text+0x1e7): undefined reference to `execute(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)' collect2: ld returned 1 exit status
Having a little trouble getting my function to display the results. I got my getNumber function working and I know I can't use return to return multiple values so I created a function that would display my results but I am a little lost on how I get the results from one function to another.
#include <iostream> #include <array> #include <iomanip> using namespace std; void printResult(int, int); void getNumber(int &, int &); void printResults (int, int){ int n, n1;
The following function uses reference variables as parameters. Rewrite the function so it uses pointers instead of reference variables, and then demonstrate the function in a complete program.
int doSomething(int &x, int &y) { int temp =x; x = y * 10; y = temp * 10; return x + y; }
I understand how to covert the reference variables to pointers, however I am stuck on this error. Either I get the error listed in the title or (with a few changes) the error "invalid conversion from 'int' to 'int*'"
What am I doing incorrectly?
#include <iostream> using namespace std;
int doSomething(int*, int*);
int main(){ int X, Y, result;
[Code] ....
I have multiplied both x and y by 10 and then added them together!
Here is the result " //I really didn't know how else to use the "doSomething" function in a meaningful way. So... I just stated what the function does.
<< result << ". "; system("PAUSE"); return 0; } int doSomthing(int *x, int *y)
So I was reading my book and it listed this piece of code. The first piece of code is in the book and the 2nd is just my test on the piece of code. I am curious as to why in the functions parameters there is a reference to aString. I've noticed that removing it has no affect on the outcome of the code.
two parameters, CImage *pImgSrc and CImage *pImgDst. I think they are class pointers and the function is passed by reference. What should I learn to understand this function and its parameters? How should I use this function? how to use the function with two parameters CImage *pImgSrc and CImage *pImgDst.
The place where I should put the return value is marked with ???. SEntityPhysicalizeParams is a struct from another header from which I dont have access to it's source file.
I tried several things but noone seemed to work out and keep getting me either error "function must return a value" or "initial value of reference to non-const must be an lValue".
Here is SEntityPhysicalize where my function is refering to:
I have a class called Point that has functions for getting and setting x, y, and z coords., distance, and midpoint. I need to write a function that prints the class and must use ostream & displayPoint( ostream & ); as the prototype. I did some googling and came up with
I'm getting an undefined reference error to a function, and I can't figure out why. I have tried letting code blocks compile the files, I have tried the command line to compile it with the same results.
I looked up the error and found this from [URL]
undefined reference Example /tmp/cc2Q0kRa.o: In function `main': /tmp/cc2Q0kRa.o(.text+0x18): undefined reference to `Print(int)' collect2: ld returned 1 exit status
Meaning / Your code called the function Print, but the linker could not find the code for it in any .o file
Usual Causes
You forgot to link the .o file that contains the function
You misspelled the name of the function
You spelled the name of the function correctly, but the parameter list is different in someway
which seems to be the error I get. I have double checked all 4 and I see nothing.
The code that specifically gives me the error is:
Item *name = new Item(desc, id, weight, loc); itemMap.addItem(name);
and the class looks like this:
class Item // Standard Items { private: std::string name; std::string desc; int id; int weight; int loc;
[code].....
I think everything matches up unless I'm just missing it.
I created the following code to pass the the variable 'inputVoltage' by reference to the function 'input'. It certainly works when I run the program, but I dont think it is a standard way of doing it, i.e. the use of '*' and '&' is not according to convention ? Or perhaps the way did it is acceptable ?
int input (double *inputVoltage); int main ( { double inputVoltage; input(&inputVoltage);
So on lines 36 - 39 (The commented out functions) is where I'm sure is causing this error because once I don't comment them out pretty much everywhere Flink or Rlink is used or defined I get this error.
