C++ :: Category And Constant Storage

Mar 14, 2013

I have a class that I'm going to use to store a category. Right now there are seven options, but there is the potential for a whole lot more in the future. So I started off by storing an integer as the private member. I then used static constants to define the numeric values to represent each category, then a set of static constant strings that corresponds to those numbers in case I need their actual names. Finally I set up some static functions to convert between the integer value and the string, and vice versa.

I'm not sure if this is the best way to go about this. For one it makes the categories names and designations unchangeable. I thought that storing them in a file would be a better option, but then i needed a container that is the equivalent of a constant.

I thought of defining a class to contain an int and the associated string. It would be designed so that it can only be initialized with both items. Then provide no functionality to change the contents. So I've basically created my own constant.

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C++ :: Std Container Iterators - Category?

Jun 15, 2014

When using an iterator with a std container (list / vector etc) sometimes it's possible to modify the container (e.g. delete an item) yet still carry on using the iterator - whereas in other cases, modifying the container immediately invalidates any open iterators on it. Is there an easy way to know which containers fall into which category? (or does it vary from one compiler to another?)

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C++ ::  Tree Data Structure To Represent Category And Subcategory Of Products

Jan 15, 2015

Given a product category and sub­category representation:

a. Come up with a tree data structure to minimally (in terms of storage) represent this
b. Write a program to convert the given representation (shown in example below) to this
c. Write a function to output the tree structure in a nice human readable format

Note:
a. There can be any number of levels of depth
b. Rows may be repeated in input, but need to feature only once in the final tree.

Example category list (read this input from a file):

everything else|office supplies
electronics|video games
electronics|video games|accessories
electronics|video games|accessories|headsets
electronics|video games|accessories|flight controls
electronics|video games|accessories|joysticks

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C :: Distinguish Between Character Constant And String Constant

Feb 20, 2015

Can distinguish between character constant and string constant giving examples

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C++ :: Unlimited Storage For Variables

Jul 12, 2013

I am working on a project and I need to save and work on very big numbers, let me take u an example :

E.g. I want to find the biggest prime number ( 2,3,5,7,... ) but I just know about int, double and etc. which have unlimited storage .

How to save very big numbers on the memory and use them ?

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C++ :: Declare Not Allocating Storage?

Jan 22, 2014

decalration won't allocate storage, while definition will. This is a test program:

#include <iostream>
using namespace std;
extern int ei;
int i;

[Code].....

Others are all fine in this program except ei.
compiler error: undefined reference to ei.

I understand ei is only declared so there is no memory address, but when I do ei=1, then ei completed it's definition, why still cannot use pei to get it's address?

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C++ :: Invalid Storage Class For A Function?

Mar 23, 2014

I made a program and when I try to use the main driver to instantiate everything it says invalid storage class for a function. All of my code is in 4 separate files i'm just trying to get it to run now.

Code:
#include "stdafx.h"
#include <iostream>
#include <iomanip>
#include <fstream>

[Code]......

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C :: No Permanent Storage During Program Execution?

May 22, 2013

Code:

#include <stdio.h>
int sum_array(int * , int );
int main(void)
{
int total = sum_array( (int []) { 1 , 2 , 3 , 4 } , 4 );
}

[code]....

We create an unnamed array "on the fly" that it means array has no permanent storage during the program execution?

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C++ :: Wedding Reception Data Storage?

Mar 4, 2014

I wanted to store information about a wedding reception and I'm having a few troubles with my program.

#include<iostream>
#include<windows.h>
#include <ctime>
#include<conio.h>
#include<string>
#include<fstream>
using namespace std;
#define on ,
void GREETING();

[code].....

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C/C++ :: Explicit Specialization Cannot Have A Storage Class

Jan 31, 2013

I am porting code from windows using visual studio to mac with xcode.

Quite a lot of issue have a appeared, which is no surprise, one warning that keeps on appearing is Explicit Specialiszation cannot have a storage class:

enum SortReturnCodeEnum {LOWEST=1, HIGHEST=2, HIGHLOW = 3, IDENTICAL=4};
template<typename tKey>
static SortReturnCodeEnum DefaultCompare(typename ArgType<tKey>::ARGT Value1, typename ArgType<tKey>::ARGT Value2)
{

[Code]....

I could do a #define __GNUC__ but i was checking

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C/C++ :: Storage Class Specifiers Concept?

Feb 15, 2013

Write a program using all storage class specifiers?

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C++ :: Two Identical Storage Containers - Typecasting

Oct 27, 2012

I have a situation where I have two identical storage containers:

Code:
////////////// multiplatform version
union _SOVector3 {
struct { float x, y, z; };
struct { float r, g, b; };
float v[3];

[Code] .....

SOVector3 is part of a namespace with specialized functions that are generic and intended for multiplatform usage.

GLKVector3 is dedicated to the Mac and has its own set of functions.

But what I want to do is freely interchange the storage between these two namespaces. Such as like this:

Code:
start = clock();
SOVector4 myVec4 = SOVector4Make(1.0f, 3.0, 6.0f, 1.0);
SOMatrix4 myMat4 = SOMatrix4Identity;
for (uint i=0; i<100000; ++i ) {

[Code] ....

But I am getting errors when I typecast this.

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C++ :: How Item Storage System Is Supposed To Work

Feb 14, 2013

So the RPG I have been making is based on this tutorial URL.....I don't entirely understand how the Item storage system is supposed to work. It looks like the array shown is for one item but, there are 3 lines of code that correlate. The author says that this is a repeatable bit of code for each item so.... i'm just completely lost. The player will have two or three to start and there are 4 battle/health items and one key ....

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Visual C++ :: Read Excel File And Storage In Array

Nov 4, 2014

I wish to read an excel file which contains the table shown at the picture below.

I don't really know how to code the direct storage of the values in the appropriate array.

For example I wish to store the countries in an array of a string type.

could I have some piece of code which illustrates it (I mean the reading of an excel file and the direct storage of his value in an array).

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C :: Storage Types / Formatted Input / Output / Processing A Menu

Feb 1, 2013

where to start and how it should be structured. how I should go about writing this program, like should i make functions, pointers, etc. And to display the menu, is it easiest to just use printf statements or is there something more efficient.

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C++ :: Access Serial Port - This Declaration Has No Storage Class Or Type Specifier

Feb 26, 2013

I am writing a code using Visual C++ to access serial port.

Code:
HANDLE hSerial= CreateFile(L"COM1", GENERIC_READ | GENERIC_WRITE,0,0,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);
DCB dcb = {0};
dcb.DCBlength=sizeof(dcbSerialParams);
dcb.BaudRate=CBR_1200;
dcb.ByteSize=8;
dcb.StopBits=ONESTOPBIT;
dcb.Parity=NOPARITY;

I am getting error in all last five lines in above code at dcb. and error is give below:-

Error: this declaration has no storage class or type specifier

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C++ :: Non Constant Member Function Being Called Inside Constant Member Function?

Dec 28, 2012

#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 .

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C++ :: Expression Must Have Constant Value?

Oct 23, 2013

line 27 and line 88 Im having a hard time figuring it out what the error is.

#include<iostream>
#include <cmath>
#include<algorithm>

[Code]....

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C++ :: Why Are All Strings Constant

Apr 10, 2013

why all strings are always constant?

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C :: Pointer Cannot Be Initialized With A Constant

May 20, 2014

Why pointer cannot be initialized with a constant like.

Code: int *p = 3000;

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C++ ::  Pass By Constant Copy

Jun 16, 2014

I have never seen anyone pass by const copy and there probably is a reason. I know that the compiler ignores top level const-ness of function arguments. There are functions which take arguments without manipulating those arguments return the result, for example the C Standard Library funcion double sqrt (double x). The function shouldn't modify it's argument, but it can since the argument isn't const.Take these two functions for example:

double square_root_1(double arg)
{
arg = 7; // we won't get the desired results
return arg * arg;

[code]....

So isn't it better to pass by const copy to make sure that you (or someone else) don't by accident modify the argument? The only disadvantage I see is that it makes the code too verbose.

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C++ ::  Random Integer Must Be A Constant

Mar 18, 2014

//VALID:
const int CONSTANT=100;
int integerArray[CONSTANT]={ 0 };

//but after getting input let's say:
cin>>randomInteger;
int integerArray[randomInteger]; // This is invalid.

// VISUAL STUDIO 13 Says : randomInteger must be a constant; If so?
const int CONSTANT=randomInteger; //This is also invalid.

How to get user defined

//Input in a constant variable?

How to resolve this? I know dynamically allocation other than this.

I am using VISUAL STUDIO 13 ....

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C++ :: Constant Declaration In Function

Jan 20, 2013

What is the difference between:

const int testFunction() &
int testFunction() const

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C++ :: Constant After Member Function

Aug 27, 2013

#include<iostream>
using namespace std;
class Student{
public:
int age;
int rollNo,marks;
string name;
void AddEntry();

[Code] .....

error: non-member function 'void Display(Student*, int)' cannot have cv-qualifier|

why and how can I solve it?

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C++ :: Replacing Macro With Constant

Apr 4, 2013

I heard that const shall be preferred over #define . So I start to change my program accordingly.

But then below error message occurs during compilation:

#include "common.h"
#include "definition.h"
#include "particle.h"
int main() {
Particle *p = new Particle();

[Code] .....

I guess the error occurs because, when the line 9 of particle.h (File 4) is compiled, value of const int dimension is not seen by the compiler.

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C++ :: Cannot Appear In A Constant-expression (list)

Aug 4, 2014

Why do I get the error 'rec' cannot appear in a constant-expression ?

I have the following definitions:

... string rec[6];
list<rec> musicList;
...

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