How I could use unions to combine registers elegantly. For example I have the 8 bit registers B and C & I have opcodes that work on each independent register such as add b, c, which is simple, but then I also have opcodes that work on both of them as if they're one like ld a, bc. I know I could go about that by just masking them together but I've seen it done with unions before & it made everything so much more simple.
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The tools Hal's sells are: Hammers: $10.99 Wrenches: $10.99 Levels: $19.99 Tape Measures: $4.99 Screwdrivers: $8.99
In order to make things easier in the long run you have decided to make a c++ program that takes in all the orders for each register and tallies them at the end of the day.
Write a c++ program that does the following:
Create a Register class that can store all of the receipts for the day and the totals for that register.
This class could have the following member functions:
Contructor(int) - Creates a number of receipts based on an integer that is passed into the constructor (this is the largest number of orders that the register can take). You may also be required to create additional variables to make the program work but that's up to you to determine.
void getorder() - Asks the user how many of each item they want an stores that in the first available receipt.
void returnreceipts() - This function returns the details of all the receipts and the total for the day.
Register operator+(const Register &right)- This is an overloaded addition operator. When two objects are added together an empty temporary register is created (with 0 receipts) and only the totals of both objects are added to it. The temporary register is returned by the function.
Register operator=(const Register &right)- This overloaded assignment operator copies only the totals from the Object on the right.
In the Main function I would like:
Create 3 Register Objects. The first two registers are the ones in the store and should be initialized to take 10 orders. The third is used at closing time and can be initialized with 0 receipts as it will only take in the totals from the other registers.
Run the getorder function for registers 1 and 2 twice.
Run returnreceipts for register 1 and register2.
Reg3=Reg1+Reg2;
Run returnreceipts for register 3.
[Code]...
this is what I have so far I'm trying to get the input part working first, so the user would be asked each item individual how many they want? this will happen for 2 users, then the next register will do the same?
I have dabbled in programming with C, but I am not proficient enough to write a program dealing with files. I have to take an extremely long list of numbers that need to be placed into another file within a line of code for validating purposes. Taking the numbers from one file and placing them into another file with a string code around them?
View 1 Replies View Related#include <stdio.h>
#include <ctype.h>
#include <string.h>
void interpose(char s[], char a[], int pos) {
char b[80];
[Code] ....
The program should take 2 string parameter and 1 int parameter for combining. (without any str functions, the functions should be written by coder)
My problem is when i enter int value program crashes.
For example,
str1='Good';
str2=' Morning';
int x= 5;
The output will be 'Good Morning'
Write a program that uses a record structure to store a Student Name, Student ID, Test Scores, Average Test Score, and Grade. The program should keep a list of test scores for a group of 6 students. The program should ask for the name, ID, and four test scores for each student. Then the average test score should be calculated and stored. The course grade should be based on the following scale:
Average Test Score Course Grade
------------------ ------------
90 - 100 A
80 - 89 B
70 - 79 C
60 - 69 D
59 or below F
A table should be displayed on the screen listing each student's name, ID, average test score, and course grade. Implement with functions.
My code runs but it isnt returning anything (readable/correct) and i have no clue why. This is what i have so far:
#include <iostream>
using namespace std;
const int columns = 4;
struct StuRec //user defined datatype {
int id[6];
char names[6][20];
[Code] .....
it compiles completely but at the end instead of showing the student name ID average score and class grade it shows.... [URL] .....
merging 2 or more pdfs using itextsharp. I have 2 methods that fill a pdf template each and saves them to a memorystream and a downloadAsPDF methods to return the combined pdfs to the broswer. the downloadAsPDF works when i add only one of the memorystream but when i add both MemoryStreams to the list I receive the message...If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document.
public byte[] fillTemplateA() {
String NfoodAllergyTemplate = "~/pdfTemplateA.pdf";
[Code].....
Write a program that uses a record structure to store a Student Name, Student ID, Test Scores, Average Test Score, and Grade. The program should keep a list of test scores for a group of 6 students. The program should ask for the name, ID, and four test scores for each student. Then the average test score should be calculated and stored. The course grade should be based on the following scale:
Average Test Score Course Grade
------------------ ------------
90 - 100 A
80 - 89 B
70 - 79 C
60 - 69 D
59 or below F
A table should be displayed on the screen listing each student's name, ID, average test score, and course grade. Implement with functions.
My code runs but it isnt returning anything(readable/correct) and i have no clue why. This is what i have so far:
#include <iostream>
using namespace std;
const int columns = 4;
struct StuRec //user defined datatype {
int id[6];
char names[6][20];
int scores[6][4];
double avg[6];
char grade[6];
}; //semi-colon required
[Code] ...
I'm having a bit of trouble with something. What I'm trying to do is create a new Access table by combining other already existing Tables.
For instance, let's consider Table1 (with columns A, B and C), Table2 (with columns A, D and E) and Table3 (with columns A, F and G), where Table1.A = Table2.A = Table3.A.
From these, I want to create a new table TableResult, with columns A, B, C, D, E, F and G, with all the data contained in them. There's one catch: I want the code to get the names of the other columns, apart from column A.
I've thought about using Union, but I need to actually create a new table by combining the previous tables.
I want to write a template that combines two type of resources:
class someClasses {
typedef someType ElementType;
} template<class T1,class T2>
class combo {
...
}
And I want to specify my T1 and T2 has the same ElementType, how can I write my combo class to partial specialize the general case so the ElementType check is at compile time?
I'm trying to use a structure in union in the following format:
Code:
union data
{
unsigned char All[10] ;
struct data_pkt
{
unsigned char ack;
unsigned short status;
unsigned short data_length;
unsigned char Data[5];
}format;
}adb; adb.
All has 10 bytes which is equivalent to the structure bytes. ie 6 bytes if unsigned char and 2 short i.e 4 bytes. Thus total 10 bytes is given to adb.All. When I print the struct size I get 12 bytes. This creates problem in obtaining data in union. According to the program:
adb.format.ack should have the address of adb.All[0]
adb.format.status should have the address of adb.All[1]
adb.format.data_length should have the address of adb.All[3]
adb.format.Data[0] should have the address of adb.All[5]
But in actual case this is how memory is allocated:
adb.format.ack assigned to the address of adb.All[0]
adb.format.status assigned to the address of adb.All[2]
adb.format.data_length assigned to the address of adb.All[4]
adb.format.Data[0] assigned to the address of adb.All[6]
Why this is happening? How can I solve this?
In the current code,We are using pointer of union and assigning value.
class sample {
union {
short *two_int;
int *four_int;
double *eight_real;
char *one_ascii;
// void *v;
}; }
Than we assign value in following way.
sample.four_int[0] = (x + xoff); ( x and xoff and y and yoff all are integer)
sample.four_int[1] = (y + yoff);
Than we write data into file. it was working fine into 32 bit machine but it is not working 64bit machine. When I compare data and found that data is divided by 4. For Ex The File generating from 32 bit machine contain 80 than 64 bit . File contain 20.
I have made VGA emulation with registers and memory in my emulator. But for some reason the writes to the union array with CPU data (register 0-8 of the VGA's Graphics Controller Registers, referenced with <GRAPHREGS>.DATA[index]) don't reflect on the union's data.
typedef union __attribute__((packed)) {
byte DATA[9]; //9 registers present!
struct //Contains the registers itself! {
//Set/Reset Register (index 00h)
union {
[code]...
what's going wrong? Have I made an error in the registers?
(In this case I write to register <GRAPHREGS>.DATA[8] (which should be the <GRAPHREGS>.REGISTERS.BITMASKREGISTER)), but the BITMASKREGISTER stays 0, while DATA[8] gets the correct value.
I have the following C++ code
typedef union UUID {
unsigned char byte[16]; /**< Array of 16 bytes. */
unsigned int ll[2]; /**< Array of two 64-bit words. */
} UUID;
[Code] ......
The compiler complains thus
$ g++ union.cpp
union.cpp: In function "int main()":
union.cpp:15:17: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x
union.cpp:15:17: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x
union.cpp:15:17: error: no match for "operator=" in "entry.EntryHeader::uuid = {0, 0, 0, 2}"
union.cpp:1:20: note: candidate is: UUID& UUID:perator=(const UUID&)
How do I go about assigning values to this union in C++.
Classes defined with struct and union
Classes can be defined not only with keyword class, but also with keywords struct and union.
The concepts of class and data structure are so similar that both keywords (struct and class) can be used in C++ to declare classes (i.e. structs can also have function members in C++, not only data members). The only difference between both is that members of classes declared with the keyword struct have public access by default, while members of classes declared with the keyword class have private access. For all other purposes both keywords are equivalent.
The concept of unions is different from that of classes declared with struct and class, since unions only store one data member at a time, but nevertheless they are also classes and can thus also hold function members. The default access in union classes is public.
The above is a statement taken from a C++ tutorial. So I understand classes a bit better now but the above quote doesnt make too much sense. Is it saying that you can have a class within a class?
What i'm interested in is the behavour of a struct/union constructed like this:
Code:
typedef struct {
uint64_t num1;
uint64_t num2;
} st_a;
typedef struct {
uint64_t num1;
uint32_t num2;
[Code] .....
What kind of behavour could I expect from object, in the following cases:
1. newsomestruct(0)->u.a.num1 = 2;
2. newsomestruct(1)->u.b.num1 = 2;
3. newsomestruct(0)->u.a.num2 = 2;
4. newsomestruct(1)->u.b.num2 = 2;
5. newsomestruct(0)->u.b.num1 = 2;
6. newsomestruct(1)->u.a.num1 = 2;
7. newsomestruct(0)->u.b.num2 = 2;
8. newsomestruct(1)->u.a.num2 = 2;
9. Code:
somestruct* ss1 = newsomestruct(0);
somestruct* ss2 = newsomestruct(1);
* ss1 = * ss2; 10. Code: somestruct* ss1 = newsomestruct(0);
somestruct* ss2 = newsomestruct(1);
* ss2 = * ss1;
This is what I'd expect, but I can't find any evidence online in C standards or elsewhere:
1. Works as expected, sets the value of a.num1 to 2.
2. Works as expected, sets the value of b.num1 to 2.
3. Works as expected, sets the value of a.num2 to 2.
4. Works as expected, sets the value of b.num2 to 2.
5. Works as expected, sets the value of b.num1 to 2.
6. Works as expected, sets the value of a.num1 to 2.
7. Works as expected, sets the value of b.num1 to 2.
8. Crashes/Memory Corruption, attempted to alter memory outside struct.
9. Works as expected, * ss1 == * ss2
10. Crashes/Memory Corruption, attempted to alter memory outside struct.
I've tested simular code on my machine (Xubuntu 14.04LTS compiled with gcc on -O3) and it appears to be reliable, given that you stick with acessing the type tagged in the struct or the common initial union struct members (in this case num1).
I have union of pointer.
union {
short *two_int;
int *four_int;
double *eight_real;
char *one_ascii;
// void *v;
};
We have write function which write into file.
fwrite (r.one_ascii, 1, i, outstr);
I found one thing,When we write function, we fill only four int in following way.
r.four_int[0] = x + xoff;
r.four_int[1] = y + yoff;
So my question,we fill four_int but write one_ascii only.As is it union of pointer. So it does not matter. I am using 64bit machine and do not have any issue in 32 bit machine.
For more information: [URL] ....
how to find out which member of union is currently set/active.
exm:
union myunion{
int i;
float f;
}
if i set myunion ob{7}, it set ob.i=7;
my q? is how to find out i is set f is not set/ not acrive
It involves some discrete mathematics. Any code snippet to get me started?
View 3 Replies View RelatedThe program is to find intersection,union and difference of two sets. The program take the input correctly but after it crashes with the message that some exe is not working...
Code:
#include<iostream>
using namespace std;
void Input(int *A, int*B, int size1, int size2)
//input function {
[Code] ....
I'm trying to come up with the union of two Vector ADT bags, so I have to overload the '+' operator, but I'm getting a bunch of error messages saying:
VectorBag.cpp: In instantiation of ‘VectorBag<ItemType> VectorBag<ItemType>::operator+(VectorBag<ItemType>) [with ItemType = int]’:
proj2.cpp:161:42: required from here
VectorBag.cpp:81:24: error: no match for ‘operator[]’ (operand types are ‘VectorBag<int>’ and ‘int’)
newBag.add(anotherBag[i]);
^
Here is the function to overload the operator:
template<class ItemType>
VectorBag<ItemType>
VectorBag<ItemType>::operator+(VectorBag<ItemType> anotherBag) {
VectorBag<ItemType> newBag;
for (int i = 0; i < anotherBag.getCurrentSize(); i++)
newBag.add(anotherBag[i]);
}
The add() function is pre-defined by me somewhere else in the code. It basically does push_back().
I'm trying to union eleven tables to call out data. Parent table is 'Events', child tables are 'SR1Laptimes', 'SR2Laptimes' and so on (there are ten SR... tables). Primary key in all tables is EventName. Parent/Child relationship is Events.EventName/SR1Laptimes.EventName etc All tables that start with SR have the same Schema. I'm trying to call out MIN(Q1) across all table but first need to Union them I believe. Here is my code.
myCommand.CommandText = "SELECT MIN(Q1), MIN(Q2), MIN(Q3), MIN(Q4), MIN(LaptimesMinutes), MIN(LaptimesSeconds) FROM (SELECT * FROM Events UNION ALL SELECT * FROM SR1Laptimes UNION ALL SELECT * FROM SR2Laptimes) WHERE (Events.Track = @track) AND (Events.Number = @number) AND (Events.Rider = @rider)";
myCommand.Parameters.AddWithValue("@track", analysisTrackComboBox.Text);
myCommand.Parameters.AddWithValue("@number", analysisNumberComboBox.Text);
myCommand.Parameters.AddWithValue("@rider", analysisRiderComboBox.Text);
I have some problem while allocating memory to a union inside structure. Below is the code i am using
ON SYSTEM1:
This works fine
ON SYSTEM2:
compiler complains saying "need structure or union type" while allocating MYSTRUCT1.
If I change:
shreyas[0].UnionAttr.struct1 = (MYSTRUCT1 *) malloc (sizeof(MYSTRUCT1)
to
shreyas[0].UnionAttr->struct1 = (MYSTRUCT1 *) malloc (sizeof(MYSTRUCT1)
This compiler on SYSTEM2 is happy. but second way does not look correct to me and compiler on system 1 complains about it. Which is the correct way to allocate memory?
If first one is correct then what should i look in for to avoid this error? Could this be an issue with compiler on SYSTEM2? If i use second method on SYSTEM2 code segfaults during malloc.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct mystruct1 {
int a;
int b;
[Code] ....
I am currently working with win32 API , for image processing, one of the windows function returns RGBA ( colors ) as unsigned int , I then split it into individual bytes by creating a union ,
Code:
union colour {
unsigned int value;
unsigned char RGBA[4];
}
to spit the int into individual bytes, my Question is there a better or my convenient way of doing this.
Any way that one could create a bitfield using the standard technique of creating a structure within a union, as follows:
Code:
typedef union {
struct {
unsigned b0 : 1;
unsigned b1 : 1;
:
:
unsigned b(n-1) : 1;
} bits;
unsigned int value;
}
BIT_FIELD_TYPE; Except, what I'd like to do is to replace all the single-bit elements in the bits structure with a single statement that creates an array of, say, 32 values. The clear advantage of this is that it could be traversed using an iterator, ...
Code:
main() {
BIT_FIELD_TYPE foo;
unsigned int i;
...
for (i = 0; i < n; i++) {
... (print out foo.bits.b[i]) ...
}
So far, I've not figured out a way to do it, either as an array, or using a pointer to iterate through the individual bits.
