Here is my code,
Code:
class A {
public:
void display() {
cout<<"A"<<endl;
[Code] .....
The compiler error is "error C2039: 'display' : is not a member of 'SP<T>'". What am I missing here?
smart pointer class is the one that take in charge of release allocated resource when itself destroyed.
recently,i want design a smart pointer class, it take in charge of release resource allocated by new or new[].
my problem how to design destructor, you should determine the pointer ptr is pointer an array or a single object.
the structure of this smart point class may be:
template<class T>;
class smart_pointer{
public:
smart_pointer(T* p):ptr(p){};
~smart_pointer(){
[Code] ......
I just want to know if there is any real difference between the two below, if yes, when would i use one over the other? I would thought the "&" is pointless in below function, as far as the data is concerned.., the only things is with "&", if the pointer address value is changed in Test function, it will affect the caller's copy of data. Both function should behave the same if data is changed.
Code:
Between
void Test(QSharedPointer<Data> data)
{
}
and
void Test(QSharedPointer<Data> & data)
{
}
Working on a basic class program and I'm generating two compiler errors that I'm not sure how to fix. Header file, implementation cpp and main cpp are shown below. The specific errors are shown after the code.
Header file Code:
#include <iostream>
#include <string>
#include <cstdlib>
#include <iomanip>
using namespace std;
[Code].......
The file generates the second error, C2228, at lines 37-41 and 43. Basically where I tried using the second created object. Error message is "left of '.setFirstName' must have class/struct/union"
Working on a solution involving inheritance. The whole solution is pretty massive at this point so I'll just focus on the problem areas. I'm getting a lot of "redefinition" and "undefined class type" compiler errors, including C2370, 2011, 2504, and 2027, in Benefit.h, Employee.h (the constant members are a big occurance) I'm also getting 2027 and 2079 in EmployeeMain.cpp. with my Benefit and Employee object calls.
Clearly I missed something in about how to code this correctly. Sadly the course textbook focuses on general OOP theory instead on the accompanying C++ syntax.
Benefit.h
Code:
#include <iostream>
#include <string>
#include <cstdlib>
#include <iomanip>
using namespace std;
[Code] .....
My compiler (GCC) keeps expecting an expression where it shouldn't in 1 specific piece of my code:
int zxcNewWindow( HWND parent, TCHAR *text, zxWINDOW *kid,
UINT style, int x, int y, int w, int h, int type )
// right here
{
*kid = zxDefWINDOW;
The project contains only 2 files right now and the settings are just the default for an empty Code::Blocks 12.11 project. Both files are in UTF-8 format (tried in ASCII too), I just cannot see why this is not compiling correctly. I'll post the files in the next two posts.
Edit: For those of you who didn't get what the error was from the above here's the full log:
mingw32-gcc.exe -Wall -g -DzxDEBUG -c C:MePrjscppzxGUImain.c -o objmain.o
C:MePrjscppzxGUImain.c: In function 'zxcNewWindow':
C:MePrjscppzxGUImain.c:39:10: error: expected expression before '{' token
Process terminated with status 1 (0 minutes, 0 seconds)
1 errors, 0 warnings (0 minutes, 0 seconds)
I am trying to run this source code but i am getting the compiler error Expression Must Have a Constant Value. I tried making both the variables x and y constants and assigned them to a significantly big number but then i am getting the error expression must be a modifiable lvalue.I have made comments in the code in front where Visual Studio is giving me the syntax error (red squiggly line).
#include<iostream>
#include <string>
#include<cmath>
using namespace std;
int main(){
int x;
int y;
[Code] ......
I am having problems compiling this program. line 29 causes the error "left operand must be l-value".
// chap5proj.cpp : Defines the entry point for the console application.
//
# include <stdafx.h>
# include <iostream>
using namespace std;
int main() {
double mph, time, disPerHour, milesTrav;
[code]....
in c program what is the difference between a compiler error and a warning
View 1 Replies View RelatedI'd like te have a heap which contains any item inserted by me. However, when I insert the values, if I delete the min value of this coded heap twice, I get the min value uncorrect.I could not find where the mistake is.
Code:
void BinaryHeap::percolateDown(int hole) {
int child = hole*2;
while (child < size) {
[Code].....
Full disclosure: this is an exercise from "Sams Teach Yourself C++ in 24 Hours" by Jesse Liberty and Rogers Candenhead. This refers to Chapter 9 (Hour 9 Activity 1)
I created a class called Point, in Point.h
I created a class called Rectangle in Rectangle.h and Rectangle.cpp
If I create an int main() function in Rectangle.cpp (that includes Rectangle.h), I can compile Rectangle.cpp and run the resulting program. Fine.
Question:
I create a separate file called main.cpp. I include Rectangle.h. But now the compiler complains.
Code:
$ g++ main.cpp -o main
/tmp/cc38JIph.o: In function `main':
main.cpp:(.text+0x26): undefined reference to `Rectangle::Rectangle(int, int, int, int)'
main.cpp:(.text+0x32): undefined reference to `Rectangle::getArea() const'
collect2: ld returned 1 exit status If I can create a class in Point.h and use it in Rectangle.h, why can I not just use Rectangle in main.cpp?
And the files, of course:
file: main.cpp
Code:
#include <iostream>
#include "Rectangle.h"
using std::cout;
using std::endl;
[Code] .....
Well, I thought I had this program working but now I'm getting the above referenced compiler error. The program is just a basic user interface. It is for a classwork assignment.
The program is to accept user information as a string, convert it (if needed) to either the int or double variable, and then display the result. I'm using stringstream convert to make the change between types, but I'm not sure if I'm using it right (that might be what's causing the error, I'm not sure). Line 36-37 generates the error.
Code:
#include <iostream>
#include <iomanip>
#include <sstream>
using namespace std;
[Code] ....
I'm trying to compile this code which is a header file.
#ifndef CUBEMAP_H_INCLUDED
#define CUBEMAP_H_INCLUDED
#include "Texture.h"
#include <string>
class CubeMap : Texture {
[Code] ....
But I get the following error:
|9|error: expected ')' before 'Directory'|
How can i resolve this?
Having issues with program to create a shape area calculator with circle square and rectangle. the uml goes as follows:
Where the UML has shape as the abstract class with public area():double, getName():string,and getDimensions:string, rectangle derived from shape with protected height, and width, and a public rectangle(h:double, w:double), followed by a derived square from rectangle with just a public square(h:double), and finally a circle derived from shape with a private radius, and a public circle(r:double).
[URL]
Have linked my program and it is giving me the following compiler errors:
error: 'qdebug' was not declared in this scope line 15 of main
error: cannot declare variable 'shp' to be of abstract type 'shape' line 22 of main
error: expected primary-expression before ')' token lines 29 -31 of main
(note previously had qstring as a header file yet changed to string since I was getting error qstring was not declared in this scope.)
I need to reverse this loop. get how to do it in order but when i have to reverse it i get a compiler error
int main() {
cout << "Enter 3 cities" << endl;
string cities;
for ( int i = 0; i < 3; ++i ) {
getline(cin, cities[3];
[Code] ....
I am trying to compile the files file1.c and file2.c using Mingw (gcc)
/////////////////////
header.h
////////////////////
#ifndef header
#define header
int variable;
#endif
[Code] ....
I would have expected a multiple defnition error when linking the two .c files. as in both the files, with the 'int variable' command, the variable 'variable' is defined (memory allocated) and during linking the linker doesnot know which variable to link to.
I get an error though when i use "int variable =123;" in the header file instead of the "int variable;" statement. i dont understand as in both the cases the variable is defined (memory is allocated) and the linker should give a multiple definition error.
I am asp.net C# developer. I decided to tackle C++, so I started today. This is probably something simple I am sure.
Code:
srand(static_cast<unsigned int>(time(0)));
int choice = rand() % NUM_WORDS;
string theWord = WORDS[choice][WORD];
string theHint = WORDS[choice][HINT];
[Code] ....
The error is happening on the last output operator, just before the jumble variable on the last line.The error is:
Code:
Intellisense: no operator"<<" matches these operands
operand types are: std::basic_ostream<char, std::char_traits<char> <<std::string
I understand what its saying, but jumble is a std::string
Here are my preprocessor directives and using statements
Code:
#include "stdafx.h"
#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;
I have been implementing a Hash Table class made, and ran into a bit of a problem in my Delete function. I have the hash table made up as
vector<list<HashNode<T,X>>> m_Table
My problem is when I iterate through the vector, and then the list in that current element to try and find the Node I want to delete, the STL list class gives me the error:
Error1error C2678: binary '==' : no operator found which takes a left-hand operand of type 'HashNode<T,X>' (or there is no acceptable conversion)
Here's the Delete function:
template <typename T, typename X>
void HashTable<T,X>::Delete(T key) {
HashNode<T,X> Node;
HashNode<T,X> NodeTemp;
list<HashNode<T,X>> temp;
list<HashNode<T,X>>::iterator it;
vector<list<HashNode<T,X>>>::iterator iter;
[Code] ....
Why it's not letting me do the .Remove() function?
Error message is identifier expected and declaration terminated incorrectly.
//to define a class Employee
#include<iostream.h>
#include<stdio.h>
#include<string.h>
#include<conio.h>
class cEmp {
[code]....
There appears to be some kind of error in by removeMin() function. Inserting items seems to work just fine but attempting to remove any items gives me the error "vector subscript out of range".
Here is my SortedPQ class... Below it you will find the quicksort implementation, in case looking at it is necessary.
template <class Type>
class SortedPQ {
private:
int front;
int rear;
vector<Type> V;
public:
SortedPQ(void) : front(-1), rear(-1), V(0){}
[Code] ....
I am new to smart pointers and have a question.If you push a smart pointer onto a vector and then some where later pop it back off it will delete the memory right?
View 1 Replies View RelatedI'm writing quite a large program that needs to work with very large arrays (up to 100 million integers). It is necessary that i can access every point of the array directly (without running through the array) and that I use as little memory as possible. I first wrote the program with pointers that point to allocated heap memory. It works fine but now I wanted to use smart pointers instead (so I'm sure to have no memory leaks). Here's a simple visualization of my problem:
#include <iostream>
#include <memory>
using namespace std;
unique_ptr<int[]> upArray;
int main() {
int nArrayLength = 10;
[Code] ....
There are 2 things that do not work how I would like the to:
1. It wants me to assign the heap memory in one step: unique_ptr<int[]> upArray(new int[nArrayLength]); But I'd like to have the unique_ptr in my Class_Declaration before I know the array length and allocate the memory later.
2. *(upArray + i) = i;
cout << *(upArray + i);
Those lines don't work! How else can I do it.
When i try to compile this code it gives me a error during run-time saying "*program name* has stopped working"
Code:
#include <iostream>
#include <memory>
using std::cout;
using std::endl;
using std::unique_ptr;
[Code] .....
Why is this happening? Also why do you need the asterisk on smart pointers to assign them a value? Is it just because, or is there a reason.
Suppose I'm writing a program designed to simulate a large company. I'm interested in tracking each company employee by the location where they work. This company has perhaps a thousand different locations:
class Employee {
public:
AccessorFunction1(); // does something
AccessorFunction2(); // does something different
AccessorFunction3(); // does something completely different
protected:
// Some data
[code]....
Once employees are created and pointers to them are saved in the proper Location vector, I write an accessor function, OrganizeLocation(), designed to do a number of operations on a given vector. The problem is, I have maybe a thousand vectors. How do I call this function and specify which vector I want?
Currently, I'm using this clunky solution:
void Company::OrganizeLocation(int a){
switch(a) {
case 1: {
for(unsigned int i=0; i<LocationA.size(); i++) {
LocationA[i]->AccessorFunction1();
LocationA[i]->AccessorFunction2();
LocationA[i]->AccessorFunction3();
[code]....
The key point here is that whichever vector I choose to operate upon, I'll do the exact same procedure every time. I hate this solution because it results in very long and repetitive code not to mention its very error-prone when you re-editing all those "LocationA 's into "LocationB/C/D/etc."
void Company::OrganizeLocation( string $WhichOne$ ){
for(unsigned int i=0; i<LocationA.size(); i++) {
Location$WhichOne$[i]->AccessorFunction1();
Location$WhichOne$[i]->AccessorFunction2();
Location$WhichOne$[i]->AccessorFunction3();
}
Or, if it can't be done in C++, is there a better design approach? Ultimately I need the Company object to hold multiple vectors but use one compact accessor function to perform operations on just one of them.
Writing a smart array class for my C++ class. I'm running into a problem where the constructor apparently throws the wrong exception. Compiled on G++ with C++11 extensions enabled.
Code:
// headers
#include <iostream>
#include <utility>
#include <cctype>
// stuff we need from namespace std
using std::cout;
using std::cin;
[Code] .....
When I try to check the error-handling code, when I enter a size less then two, Array's ctor throws InvalidSize, and gets caught, all good. But when I enter a letter, the ctor also seems to throw InvalidSize!
I am trying to use smart pointers to sort and re-link potentially large data elements. I have defined a class in my code for smart pointers, as listed below:
template <typename T>
class sptr {
public:
sptr(T *_ptr=NULL) { ptr = _ptr; }
[Code] ....
The object I'm trying to sort is a singly-linked list containing class objects with personal records (i.e., names, phone numbers, etc.). The singly-linked list class has an iterator class within it, as listed below.
template <class T>
class slist {
private:
struct node {
node() { data=T(); next=NULL; }
[Code] .....
The following is my function within my list class for "sorting" using the smart pointers.
template <typename T>
void slist<T>::sort(){
vector< sptr<node> > Ap(N); // set up smart point array for list
//slist<T>::iterator iter = begin();
node *ptrtemp = head->next;
[Code] .....
I must have a bad smart pointer assignment somewhere because this code compiles, but when I run it, std::bad_alloc happens along with a core dump. Where am I leaking memory?
