I am not exactly sure how to do this and i keep running into problems. This is my code here that works.
Code:
#include<iostream>
using namespace std;
struct record {
double quiz1;
double quiz2;
double midyear, midyear_one;
[Code] .....
I have a struct that I'm writing in C and need to use a mex function to use it in matlab. The struct was originally in matlab and need to have the variables:
force = feval(forcing, Euler, Euler.x(:,k));
q = squeeze(q(:,k,:)/>/>);
q0 = squeeze(Euler.q0(:,k,:)/>/>);
nx = Euler.nx(:,k);% normal vector
J = Euler.J(1,k);
rx = Euler.rx(1,k);
qh = reshape(qh(k:k+1,:)/>/>,[],1);
k = k;
The mex function I have come up with is:
#include "mex.h"
/* Extract local info for element k */
/* local struct */
typedef struct {
double force;
double q;
[Code] ....
I just read and have known for a while that classes are private (members and inheritance) by default and structs are public. But my question then comes what if.. a struct inheriting from a class or a class inheriting from a struct?
View 3 Replies View RelatedSandy is of class Person, who converts to Muslim and takes on a new name Fatima, and has all the attributes of Sandy, with new Muslim attributes (e.g. religion == Islam, etc..). At this point, Sandy can be deleted, and Fatima, now of class Muslim will play Sandy's role henceforth. The problem is that due to her new address, all the people who knew Sandy does not know Fatima. Manually changing Sandy's address to Fatima's address for all those people who knew Sandy is clearly not an acceptable method. I looked through all the design patterns and cannot find one to solve this problem. how to improve the design? Here's my simplified code showing the problem:
#include <iostream>
#include <string>
#include <typeinfo>
class Person {
std::string name;
Person* bestFriend;
[Code]...
Output:
sandy = 0x32658, 6Person
Mary's best friend is Sandy.
fatima = 0x23fec0, 6Muslim
Mary's best friend is Sandy.
Of course, we want to have: Mary's best friend is Fatima,. with mary->getBestFriend()->getReligion() == Islam, etc... How to redesign the whole thing so that this is automated (assume there are thousands of people who know her)?
Version 1 (works fine)
Creating array in main and then calling a sorting function from sorting class.
In main:
const size_t SIZE = 100;
int *array = new int [SIZE];
//fill array with ints, not shown here
quickSort(array, SIZE); //calling the sorting function in the sorting class
In the sorting class, quickSort is declared as such:
void quickSort(int arr[], int num);
Everything works great.
Version 2 (issues)
Instead of creating the array in main, I have set up a class for the array, MyArrayClass, where I create an object containing the array of ints. So far so good. The issues come when I write a member function to call quickSort. Even though my MyArrayClass object contains an array of ints, the code calling for quickSort() won't compile as the data type isn't ints but MyArrayClass (which in turn holds ints though). The compiler (using VS 2013 btw) complains that quickSort can’t convert the first argument from 'const MyArrayClass' to 'int[]'.
How do I cast my class object array of ints as an int[] in order to be able to call the quickSort function? Or should I solve this issue in some other way? I tried altering the sorting function to accept the object as it is, but that only created an avalanche of new errors, so thinking that converting/casting the object array --> int[] might be easier...
I am trying to write a Fraction class and getting the following warning when compiling my code :
Fraction.cpp: In constructor 'Fraction::Fraction(double)':
Fraction.cpp:8: warning :converting to 'int' from 'double'
My Fraction.cpp class looks like :
#include "Fraction.h"
Fraction::Fraction(int n, int d):num(n),den(d) {
cout << This is double param constructor <<endl;
}
Fraction::Fraction(double d):num(d),den(0)
[Code] ....
How can I get rid of the warning ?
I've been working on a path-tracer for some time, and all along I've used structs instead of classes for vectors and matrices. Today I changed all of them to classes instead, changing none of the actual function bodies themselves, and the results were miserable to say the least.
Here's a render form before the change: [URL] ....
And here's the same render after: [URL] ....
Why this is happening, considering that none of the actual function-bodies have been changed, except for what little is needed to make the change from class to struct.
I'm writing a class to store a tree I have a small issue.
I have a class which stores a node of the tree, something like this:
template<class T>
class node {
private:
(stuff regarding parent node and child nodes);
T __data;
public:
// more stuff (constructors and utility functions) here
};
And I want to I want to be able to do the conversion T(node<T>) implicitly. For example, I want to be able to do this:
node<int> myNode;
myNode=5;
myNode+=10;
myNode*=9;
int x=int(myNode/4);
cout << x+myNode;
And this:
class myClass {
int x;
int y;
void print () {cout << x << ' ' << y << endl;}
[Code] ....
How could I achieve this?
while writing code i got a question. For example i created a class named as unit.
Think a simple game, and the unit class will belong the units.İf i give the preferences as private one by one, it will be irregular. For a detailed game; height, weight, race, hair preferences, eyes... Strength, dexterity, charisma, intelligence, wisdom, constution... experience, damage, armor...
and should i use struct to group them? And how to can i use struct at the inside of class as private?
I'm trying to learn as much C++ as I can. I was writing a program that mixes linked lists and classes. There is the class "Obj" which only holds an integer called 'data' and the classic "struct node" structure for linked list, but this time the "node" structure will hold an instance of "Obj" Class and the next* pointer.
#include <iostream>
using namespace std;
class Obj {
private:
int data;
public:
[code]....
I am making a snake game just to give some context.
//LevelObject.hpp
class LevelObject {
public:
virtual void Update() = 0;
virtual void Draw(Canvas& canvas) = 0;
protected:
Vector3 location_;
[Code] ....
The problem I have is with the Size constructor and the abstract class LevelObject which size is a member of.
The compiler error I get is:
C:Program Files (x86)ProgrammingProjectsUniversityprg_interactivesnakey_takeysrc..inc..incPlayer.hpp|17|warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]|
C:Program Files (x86)ProgrammingProjectsUniversityprg_interactivesnakey_takeysrc..inc..inc..incPlayer.hpp|17|warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]|
[Code] .....
However I do invoke the copy constructor when I pass a variable of type size to the constructor in this line:
size_ = Size(s);
But the problem is that its complaining that the abstract class LevelObject doesn't invoke the constructor, which it shouldn't.
I have an assignment that is due on monday I am stuck on this function. I have to convert my netpay which is a float to a string So if i have 356.26 it should output the sum of three hundred fifty-six and 26/100 dollars my program function works for the sum of three hundred but after that it spits out garbage.
Code:
void convertNetPay(float netPay, char *netPayString) {
int numHuns, numTens, numOnes;
char OnesTable[9][8]={"One","Two","Three","Four","Five","Six","Seven","Eight","Nine"};
char ResultString[10+1];
[code].....
Is it any different when using a class in my code. My previous code i define my struct like this
Code: #include <iostream>
#include <fstream>
#include <string>
struct{
[Code] .....
or do i still define it the same way at the top of my code.
How to get relative memory address of members of Class or Structure ? I want to auto scan the members of Class/Struct, and show the address/value like the "watch window" in debug mode of popular C/C++ IDE software.
View 2 Replies View RelatedI would like to have a unmodifiable standard of WAVEFORMATEX defined as a member of a class of mine. Something like:
class InputTest {
public:
const WAVEFORMATEX StandardWaveFormat;
public:
void TakeInput(WAVEFORMATEX pFormat);
};
Then in my cpp file to hard-code the values:
WAVEFORMATEX InputTest::StandardWaveFormat {
//Instantiate WaveFormat -- PCM standards
StandardWaveFormat.wFormatTag = WAVE_FORMAT_PCM;
StandardWaveFormat.cbSize = 0; //extra information sent over stream. Usually ignored in PCM format.
[Code] ....
I get the following errors starting with the header file:
Error1error C2146: syntax error : missing ';' before identifier 'StandardWaveFormat'
Error2error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
both associated with the "const WAVEFORMATEX StandardWaveFormat; " line.
Here's a link to the WAVEFORMATEX struct: [URL] .....
Then the cpp source code is probably way off. Let me know if you'd like to see the errors associated with that.
Can typedef and struct be put inside a class like below?
Code:
class classA {
private:
typedef void(classA::*aFnPtr_t) (); //pointer-to-member function
struct strctA {
int a;
int b[100];
};
typedef struct strctA strctA_t;
typedef void (classA::*bFnPtr_t)(strctA_t*); //pointer-to-member function
...
}
This program is suppose to store input from a user (example 14 15 27) and output it three times. Once to confirm the input using the get function to recall the data, once to look like military time (14:15:27), and once to look like slandered time (2:15:27 p.m.).
The program runs, but this is what I'm getting:
I'm thinking its because I'm using the same integers to store two sets of data. I tried to create different integers for every set of data it didn't seem to fix the problem. The fact that the program is running makes trying to figure out where the problem quite confusing to say the least.
Code:
#include <iostream>
using namespace std;
class time {
private:
int hr, min, sec;
[Code] ....
The below code is working fine in VS2008 and not working in VC6.0 (taking garbage values) this code is for converting hex values to string.
sending Input string is : 727332333263 required output: rs232c
DWORD AsciiToString(LPCTSTR f_chInputChar, LPTSTR f_chOutputChar) {
long ch;
int i,j;
TCHAR tmp[2];
int len = _tcslen(f_chInputChar);
[Code] ....
As a starter project I want convert a Neural net app from "AI Techniques for Game Programming (2002 Buckland)" to a Visual C++ CLI Forms application. I have created the interface and now I have to rewrite the in/output routines, amongst other things.
First question I have has to do with variable initialization used by Buckland. Code looks like this:
Excerpt from header file (CNeuralNet.h):
//-------------------------------------------------------------------
//define neuron struct
//-------------------------------------------------------------------
struct SNeuron
{
//the number of inputs into the neuron
int m_NumInputs;
//the weights for each input
vector<double>m_vecWeight;
[code]....
Question I have: what is the the function of ": m_NumInputs(NumInputs+1)" after the method declaration? Buckland does this in many places in his code. In this case it's a struct, but he does it with classes too.
i've defined an strcuct in .h file and i read its variable in a method in .cpp file ,but i'v got error.
.H file:
class myclass{
public:
struct opt_struct
[Code]....
when i declare the struct without static , it doesn't recognize my struct and with static i face linker error:
Error33error LNK1120: 1 unresolved externals
I am trying to create a class type structure using struct instead of classes.
Code:
#include <iostream>
#include <stdlib.h>
using namespace std;
struct myclass {
int * array;
int nelements;
[Code] ....
Guess what I am asking is using the pointer in the first code section better or is there another way'. I don't know about making the second code work.
at my work we use a static analysis tool and it is pointing out some uninitialized variables. One of which is a class member variable which is a C struct. Now, that variable is already declared in the header file for the class.
Currently in the class constructor I am doing:
Code:
memset( &thestruct, 0, sizeof( thestruct ) );
Is there a C++ way to do this? I Googled this but all I really found was:
Code:
StructDef thestruct = {};
Which doesn't really apply here.
I followed a tutorial to load a bitmap from file and convert it to a array of bytes to access it directly. Now to display the bitmap on screen do I have to convert it to a HBITMAP or can I display it from the array of bytes?
Also the program I am building is a calendar program and I need to know if I can manipulate the bitmaps pixels in the byte array (e.g change color and resize image)
here is the code to load the bitmap
HTML Code:
BYTE* Sprite2::LoadBMP(int* width, int* height, long* size, LPCTSTR bmpfile ) {
BITMAPFILEHEADER bmpheader;
BITMAPINFOHEADER bmpinfo;
DWORD bytesread;
HANDLE file = CreateFile(bmpfile,GENERIC_READ, FILE_SHARE_READ,
0, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, 0);
[code]....
Write a C++ program that adds three binary numbers of 8-bit each. Every number is stored into an array of 8 elements.
Example:
Array A
0 1 2 3 4 5 6 7
0 1 1 0 1 1 1 0
+
Array B
0 1 2 3 4 5 6 7
0 1 1 0 1 1 1 0
+
Array C
0 1 2 3 4 5 6 7
0 1 1 0 1 1 1 0
Store the result into an array D of 8 elements. Your program should show the decimal numbers for every binary number. Print screen of 6 answers. This means you should try your program six times with different numbers in every run and show the printed screen result.
I've been wondering about something for a while:
Is it possible to declare a struct/class, in a cpp file, designed for local use, but with internal linkage?
The usecase is that every once in a while, I want to wrap "startXXX+endXXX" function pairs in a simple RAII struct. I just declare the struct in my cpp and use it once.
However, if I do this, (AFAIK), the compiler will generate an entry in the link table, which means I could potentially have link conflicts if I declare the same struct twice in two different cpp files.
Unless I'm mistaken, since the struct is declared in the same cpp that it is used, I wouldn't need external linkage. Is there a way to avoid it?
I'm trying to build the gtkmm library using MSVC. One of its source files declares a struct called BuiltinStockID together with some objects of that type - e.g.
Code:
// In the header file:-
namespace Gtk {
struct BuiltinStockID {
const char* id;
[Code] ....
GTKMM_API is obviously _declspec(dllimport) (or export) as appropriate. It seems a bit unusual to use extern in addition GTKMM_API but the code won't compile if I try to exclude it. The actual instantiations are in one of the library's source files- e.g.
Code:
// In a source file
const Gtk::BuiltinStockID APPLY = { GTK_STOCK_APPLY };
const Gtk::BuiltinStockID CANCEL = { GTK_STOCK_CANCEL };
const Gtk::BuiltinStockID OK = { GTK_STOCK_OK };
GTK_STOCK_APPLY etc are simple strings such as "gtk-apply". They mostly refer to image files for the library to load (in this case, for dialog button images) although that's probably not relevant to the problem.
If I run dumpbin /EXPORTS on the built DLL it does seem to have some exported symbols with the names Gtk::Stock::APPLY, Gtk::Stock::CANCEL, Gtk::Stock::OK etc. However, if I write this in one of my own source files:-
Code:
Gtk::BuiltinStockID MyStockID;
MyStockID = Gtk::Stock::CANCEL; // <--- debugger reports <Bad Ptr>
You can see that the Gtk::Stock::CANCEL object is invalid (my debugger reports it as a bad pointer). Likewise, if I try to pass Gtk::Stock::CANCEL as a parameter to a function.
