why can't << operator be overloaded as a member function is it because that is the way c++ is written and you just can't or is there another reason because I'm confused.
View 2 RepliesI'm trying to assign a value to a member of a struct that I called via an overloaded [] operator. I have the following code for the struct:
typedef struct {
float r, g, b, a;
float operator [](int pos) {
switch (pos) {
[Code] ....
And what I wish to do is
MyStruct a;
a[0] = 0.5;
Is it possible with a struct? How to express this to search engines so I haven't been able to find anything about it. If this is not possible with a struct, is there a way to define something that can do all the following things:
SomeStruct test = {0.5, 0.5, 0.5, 1};
test.g = 1.0;
test[0] = 0.0; // test[0] would be equivalent to calling test.r
float somevalue = test[3]; // test[3] would be equivalent to calling test.a
I hope I've been sufficiently clear.
I get the following error in XCode whenever I try to access the member I created 'randomGen' in a separate class in a different header file. I have made sure to include the header file and have tried to access it through an object.
This is the code I enter when trying to access the method from randomiser.h in main.cpp. It is also an overloaded function with doubles and integers:
RandomG randomiser;
randomiser.randomGen(); // 'Call to member function 'randomGen' is ambiguous'
This is the code inside randomiser.h:
#include <string>
#include <iostream>
using std::string;
using std::cout;
using std::endl;
class RandomG {
[Code] ....
This is the error inside xcode: [URL] ....
I have tried seperating the code for the functions in another class (main.cpp) and then running and it seems to works, so I'm not sure why I can't put everything in the .h file and then access it?
I would like it in a seperate file so it doesn't clutter my main. I am writing a game with SDL so that might be confusing and I would like the window to have a random title and other random properties, so it would be easier to use a function.
I don't exactly know how to test my ==friend function in my main.
Here is my .h file:
#include<iostream>
using namespace std;
class Car{
public:
Car();
Car(int yer, string mke);
[Code] ....
I have a class matrixType that has some overloaded operators (+, -, *, and <<). With a view to having clearly-delineated, perfectly-formatted, four-sided matrices, as shown below:
A = 1 2 3
4 5 6
7 8 9
or
A + B = 1 2 3
4 5 6
7 8 9
and NOT this jagged ones shown below:
A = 1 2 3
4 5 6
7 8 9
or
A + B = 1 2 3
4 5 6
7 8 9
,
I want a scheme in which the string literals (A, A+B, etc.) could be passed as parameters to the overloaded stream insertion (<<) operator function so that I could use the string’s length to determine how much offset from the display screen’s left to apply to each matrix’s row (by using the setw() function). However, I do know that the << operator is a binary operator, meaning the function cannot take more than two parameters: that is what compounds my problem!
I want to create a program that shows the total of 2 subjects & percentage of student using binary operator overloading with member function in C++.
View 10 Replies View RelatedConsider the class specification below. Write the prototype (i.e. header) of a member function to overload the insertion operator (i.e. <<). The << operator is to output the data members of an instance of class StudentTestScores into an output stream. Your definition should allow for chaining of output operations (e.g. cout << x << y; where x and y are of type StduentTestScires).
#include <string>
using namespace std;
class StudentTestScores{
private:
string studentName;
float *testScores; // used to point to an array of test scores
int numTestScores; // number of test scores
[code]....
What is another way I could convert string to int in this overloaded operator? This way gives me an error.
Code:
istream &operator>>(istream& in, MasterData& d) {
string value;
getline(in, d.playerId, ',');
getline(in, d.firstName, ',');
getline(in, d.lastName, ',');
[Code] .....
I have two possible questions; can you use a ternary operator to initialize objects with overloaded constructors like
class thing
{
int x;
int y;
[Code].....
I can get around it if I need to but I'd like to learn more about the ternary operator if I can, since I couldn't find anything online that addressed this particular issue, at least in a way I could detect.
I'm using some overloaded operators (addition, subtraction and variants of) in part of my final major project and, when coming to test it, I've noted that they appear to be killing my pointers eventually.
I say pointers, it's always the same one. But I have isolated it to being the operators. The only two I'm really using are += and -=, though I've defined the others for consistency.
Either A ) what it is I've done wrong (if I have) or B ) why I would see this behaviour. Or, you know, if there's something glaringly obviously wrong with the code that I'm glossing over.
Code is as follows
#pragma once
#include "stdafx.h"
namespace gunpei {
/**
A paired register in the form of r1r2
Enables using two separate arrays for register processing
provides logic for assembling pair and breaking back into individual registers
*/
class GBPairedRegister {
[code]....
I designed a class template to create unique arrays. I was able to successfully input data to and output data from my array objects, irrespective of the datatype. However, I can't for the life of me fathom why my overloaded assignment operator worked perfectly well only for integer datatype and not for double/string datatypes.
Here is the class definition:
template <class dataType>
class myArray {
public:
void setArrayData();
[code]....
And here is the definition of the overloaded assignment operator:
template<class dataType>
const myArray<dataType>& myArray<dataType>::operator=(const myArray<dataType>& rightArray) {
int i;
if(this != &rightArray) {
delete [] arrayPtr;
[Code] ....
And here is my main function that tests the operations on objects of the class:
int main(){
//object declarations
myArray<double> list(5); //a single-parameter object declaration of class myArray
myArray<double> myList(2,13); //a two-parameter object declaration of class myArray
[code]....
The problem I'm having starts from where the assignment operator is being tested: for double and string datatypes, the upper input/output section works fine, but the assignment section freezes the display until the program execution is manually terminated!
I've got the following code with output. I can't figure out myself why it's what printed out there. I believe, it has something to deal with overloading/overriding/virtual functions implementations in C++:
class Base{
public: virtual void f(int);
virtual void f(double);
}
[Code].....
Thus here're my conclusions:
1) in line
d.f(1.0);
for some reason compiler preferred casting double->int of the argument and then call to 'Derived::f(int)'.
2)in line
pb->f(1.0);
for some reason compiler preferred call to 'Base::f(double);'. 'Base' is static type of pb, but the dynamic type is 'Derived'.
I believe the answer has to deal with the fact whether virtual table contains in addition to functions' names also the types of arguments they accept. AFAIK, vTable doesn't include such info.
I am working on an assignment in which i have to perform th following task
myClass itsObject1,itsObject2;
itsObject2=5000+itsObject1;
I have defined overloaded operator as follows in the header file but in the cpp file of the class it gives error.
friend vli &vli::operator + (int &a,vli &obj);
How to define it in cpp file of my class?
The task is to use the assignment operator of a class, but change all the data except certain ones. For example, below we are to assign all Person data of 'other' except for 'name' and 'ID':
#include <iostream>
#include <string>
struct Person {
std::string name;
int ID, age, height, weight;
[Code] .....
Name = Bob
ID = 2047
Age = 38
Height = 183
Weight = 170
Name = Frank
ID = 5025
Age = 25
Height = 190
Weight = 205
Bob pretends to be Frank, but keeps his name and ID.
Name = Bob
ID = 2047
Age = 25
Height = 190
Weight = 205
But I think the way I did it is pretty lousy (note the wasted steps changing the name and ID only to revert them back? So the ideal solution should require no wasted steps, unlike the method above, and changes to what the exclusions should be should be in only one place (not two like above). Of course, we assume that Person shall have many, many data members (and constantly increasing), so that simply defining Person::operator= (const Person& other) to handle all data except for 'name' and 'ID' is out of the question.
In my MFC, CMyPorpertyPageDlg is derived from CPropertyPage. How to access its member function from a nonmember function in the same CPP file?.
void Non_Member_Get_PorpertyPage()
{
CMyPorpertyPageDlg* pPageDlg = ....
}
Here is a sample of my question
class Base{
public:
int getNum();
private:
int numToGet;
}
class Derived: public Base {
public:
friend ostream& operator<<(ostream& output, const Derived &B);
[Code]...
I keep getting this error in my code. I believe it is because to use pow(x,y) both x and y have to be double, but how do i put that into my formula under calculations?
#include <iostream>
#include <cmath>
#include <iomanip>
#include <string>
#include <fstream>
using namespace std;
int main() {
// Declaration section: Declaring all variables.
[Code] ....
If I wanted to call a member function inside another member function, how would I do that, if it's possible?
For example, if I have Find(int key) defined already and wanted to call it while i was overloading operator+.
I need to return taxes paid and net pay by pass referencing a gross pay overloaded function. Are the values returned from calling the overloaded function file stream objects? Can they be passed simply through a pass-by-reference function?
//Read Data from File, gather info and calculate pay, output data to file
while(counter < x) {
inFile >> last_name >> first_name >> hours_worked >> hourly_pay;
outFile << first_name << " " << last_name << " ";
outFile << calculate_gross_pay(hours_worked,hourly_pay);
counter++;
outFile<<endl;
[code].....
#include<iostream>
using namespace std;
#include<string>
main() {
cout<< "donner votre nom:";endl;
string nom("sans nom");
cin>> nom;endl;
cout<< "votre nom est:"<<nom; endl;
return 0;
}
when i try to build this program, i get this masseges:
in function 'int main()':
statement cannot resolve address of overloaded function
this a picture of the errors:
I can't seem to figure out whats causing this error: statement cannot resolve address of overloaded function . Error is before line 14 in bubblesortrand function. Thnx in advance.
void bubblesort(int num[], int a_size)
{
int i, j, temp;
for(i = (a_size - 1); i >= 0; i--)
[Code].....
The question involves me writing a program using a overloaded function to calculate the Weekly rate of employees but they get paid hourly and weekly. I get this error but do not know why,
#include <iostream>
using namespace std;
int calcWeeklyPay(int paidWeekly, int annualSalaryWeekly)
//Returns the Weekly salary of weekly paid Employees
int calcWeeklyPay(int paidHourly, int annualSalaryHourly)
//Returns the Weekly salary of Hourly paid Employees
[Code]...
I'm stuck on the last part of my program. The directions are the following~
Expand the program to add an overloaded function to handle floating point numbers (i.e., doubles). Include output for one list of integers and one list of doubles. Use this function prototype: double avgx(double&, double&, int, ...);
Compile and run. You should have one function named avg, one named davg, and two functions named avgx
My code does not compile and I think I'm not declaring my function prototype correctly?
#include <iostream>
using std::cout;
using std::endl;
#include <cstdarg>
// function prototype(s)
int avg(int, ...);
[Code] ....
I am so close to finishing this program. It will find the median of an array of 5 values. I have one last error that I cannot seem to get to go away. Here's the code:
#include <algorithm>
#include <functional>
#include <array>
#include <iostream>
using namespace std;
int main() {
int integer1, integer2, integer3, integer4, integer5;
[Code] .....
The error states: "IntelliSense: no instance of overloaded function "std::nth_element" matches the argument list, argument types are: (std::_Array_iterator, std::_Array_iterator, unsigned int, std::_Array_iterator)
#include <iostream>
class Hello {
public:
void Test() {
[Code].....
As i know a non-constant member function cant be called inside a constant member function but how the above code has been compiled successfully and giving the expected result .
Hey I am trying to use the getline() function to read a line from a file. For some reason Visual Studio 2010 gives me the following error. "No instance of overloaded function "getline" matches the argument list". The piece of code that produces the error is in a class in a separate .h file and is executed as a method of the object. I'm almost certain it has something to do with either the compiler thinking I am calling another getline in a different namespace or my parameters for the function are incorrect. Here is the code:
Code:
#include <iostream>
#include <string>
#include <vector>
#include <fstream>
using namespace std;
class InsultGenerator
[Code] .....