I know that you're allowed to use a char pointer to access any object but are you allowed to inspect a char array with a different type, say an unsigned integer without breaking the strict aliasing rule? My understanding is that it's not legal and could lead to trouble with trap representations but I just wanted to make sure.
View 4 RepliesHow can i write a function that will read an "unsigned integer" into a variable of type "unsigned short int"? i can not use cin >> inside the function.. so i am looking for atleast a hint!
View 16 Replies View RelatedI am trying to assign the integer value to unsigned char array. But it is not storing the integer values. It prints the ascii values. Here the code snippet
Code: uchar uc[100];
for(i=0;i<100;i++)
{
uc[i] = i;
}
The values which are stored in uc[] is ascii values.I need the integer values to be stored in uc[]. I tried to do it with sprintf. but the output is not as expected. if I print the uc[i] it should diplay the value as 0,1,2....99.
Is it really needed to specify 0 as an unsigned integer? I mean 0 is always 0 regardless it's signed or not, no? In the below example is the 0U really needed?
#include <stdio.h>
unsigned invert(unsigned x, int p, int n) {
return x ^ (~(~0U << n) << p);
}
int main(void) {
[Code]...
Consider this piece of code from the following website: [URL] .....
Code:
unsigned intx = 50;
x += (x << 2) + 1;
The website above says the following about the code:
Although this is a valid manipulation, the result of the shift depends on the underlying representation of the integer type and is consequently implementation-defined.
How exactly would a legal left shift operation on an unsigned integer result in implementation-defined behaviour?
I need to create a stack with the container being an unsigned int. I tried to put in numbers up to four bits each and have the program read the numbers individually. This is the code I am using:
void push(int n)//item n is pushed onto the stack, throw exception on full stack {
string str="Error";
if (isFull())
throw str;
[Code] ....
When I have tested it, the program is reading the numbers as one whole number. For example, I put in the number 2, and it displays the number 2. Then I put in 2 again, but this time it displays the number 10, instead of 2 2.
Looking for extended unsigned integer class, that has custom lenght?
The reason i am asking is because i need an extremely large integer number, in fact one that has no theoretical limit(or at least an extremely large one).
I have an embedded microcontroller system communicating with a similar system by radio. The api for the radio requires data to be transmitted as an unsigned char array. It will always transmit a positive integer in the range 0 to 255.When I receive the data I am having difficult in extracting this positive integer.
Code:
unsigned char rxData[4]={'1','2','3',''};
int inVal=0;
//want to assign inVal whatever number was transmitted
E.g. 123
I've been at this for a week and have tried at least 10 different approaches including the use of the atoi(), copying the absolute value of each element of rxData into another char array, reinterpret_cast, and others.
I am using a structure , and when i am assing values i get the warning message , how do I avoid that ?
Code:
// header file
typedef struct {
unsigned _T_ipset:1;
unsigned RTCSetNewTime:1;
unsigned PassWord:1;
unsigned UserReset:1;
unsigned PCDEBUG:1;
unsigned PWRUP:1;
unsigned HostTaskShift:1;
unsigned TimeToConnMstr:1;
unsigned En_Display_Lcd:1;
}
[code]....
large integer implicitly truncated to unsigned type
I am new to c programing and I had spend 2 days on a program and I can't fix the error:
Code] ....
gcc Test.c -o Test.exe
/tmp/ccZkbk0V.o: In function `f':
Test.c:(.text+0x2f): undefined reference to `sqrt'
collect2: ld returned 1 exit status
Tthe program I am working in is:
#include <stdio.h>
#include <math.h>
int f(int x){
return (sqrt(4.0 - x*x));
[Code] .....
I'm trying to write some code that will integrate a function using the Trapezoid Rule. Using an online calculator I know the result should be 36621130.371094 but instead my code is giving me 31232938.000000 ....
#include <stdio.h>
#include <math.h>
int main() {
long sum1;
float i, area;
[Code] ...
I am used to the restrict keyword to hint the compiler that no overlap is going to happen in the values passed to the function.
void foo( int * restrict a, char * restrict b)
I understand that I can pass by reference in c++.
void foo( int &a, char &b)
Using it, will it automatically restrict it or not ? It is very important for performance reasons (no checks at each iterations/steps)...
So, one can do stuff like this using #defines:
#include <iostream>
#include <array>
#define x arr[0]
#define y arr[1]
#define z arr[2]
class Point {
[code]....
... that is, to be able to reference the same data by "member variables" as by referencing a stl container. But defines are the devil's work - adding in a "#define x arr[0]" is a dangerous statement. I'd really like some nice clean C++ method (C++11 or C++14 are just fine) to do this without defines, but so far I'm drawing a blank. If arr wasn't an STL container, if we just wanted a pointer-based array, I could do it this way:
class Point
{
...
float x __attribute__ ((aligned (sizeof(float))));
float y __attribute__ ((aligned (sizeof(float))));
float z __attribute__ ((aligned (sizeof(float))));
float*const arr = &x;
};
... but you obviously can't do that if arr is an STL container.
The best I've come up with is to make x, y, and z function pointers, but then you can't call them like p.x, you have to call them like *p.x(), it's not very clean and I'd expect some added overhead. One could go even uglier and make x, y, and z be instances of some custom class with overridden operators that reference arr[], but that seems like it'd be just getting ridiculous in terms of overhead (both coding and performance)
I have been playing about with Vertices and Colors and have ended up with this:
template < std::size_t SIZE, typename T >
struct Pack
{
[Code].....
Is there anyway to make an alias for Pack's data field? Something that would allow me to write:
Color3f my_color;
my_color.red = 0.1f;
i just want to break the loop when user hit ENTER.But after that programm is stil working, i don't know why, becouse i have a code just like in book, i spend a lot of time with it.
int getinfo(student pa[], int n){
cout << "START" << endl;
int i = 0;
for(i; i < n; i++) {
cout << "Studetn name";
char name[SLEN];
[code].....
Code:
while(x==1){
for (i=0;i<j;i++)
{if (word1[i] == word2[i])
{prefix[i]= word2[i];
counter++;}
else
x=2;}
Basically after the 3rd run of the for loop, it encounters a contradiction. I want it to exit right there and then. Instead it continues to run the for loop. What can I do?
I'd like to know how I could break a float into individual bytes for binary use.
Sounds simple, but it seems as though the compiler doesn't realize everything is just a series of bytes.
I'm get input from the user and then storing it in "s " and then trying make tokens, but it is not working, and after making tokens I'm counting them. Here is My Code
Code:
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
int main(){
string s;
[Code] ....
Here is my Output
Enter text:
Entered Text is: This is String
token 1: This
token 2: is
token 3: String
token 4:
Number of tokens: 3
The problem is that i want to store the first two strings "This" and "is" into two variables and how to remove token 4: which is unnecessary .
I have function that returns historical data. I can access it, using file name. If I use file name, it reads that file and saves it to dictionary, so that in the future, if historical data is required for the same file, it does not read it again (it's lazy loading). If no file is supplied to the function, it tries to read file which is given in app settings.
However, for unit testing, I do not want to read any file. Instead, I want it to use small sample of hardcoded historical data. In order to do that, I think, I need to introduce interface to it. Then I can use some IoC to choose between different implementation for unit testing purpose and ordinary launch of application.
Function to get history is given as follows:
public static class Auxiliary
{
private static Dictionary<string, MyData> _myData;
public static MyData GetData(string fileName = null)
{
// ...
}
}
I have created default Unit Test project with Visual Studio so, as far as I know, by default it uses MSTest as test runner and MSUnit as unit testing framework but it does not have any IoC container so I should manage NuGet packages for solution and install Unity.
As far as I know, MSUnit (aka Moles) can unit test static methods (it's unconstrained isolation framework, like Typemock Isolator, unlike NUnit) but still many people suggest not to use any static methods for unit testing.
Should I use shim or stub [URL] Stubs should be used for faking external dependencies and here it is not external library, but my own code.
I'm trying to make sure my code is written in smaller modules, so my first step is to create my initialization process in and external file to load the necessary data from external sources and set up things like the content of drop down list boxes.
My first attempt failed to give me access to the combobox items add function so I moved that code back into the form1.h file:
Code:
public:
Form1(void) {
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
void AddDate(char *date, int ID)
{
this->comboBox1->Items->Add("line 1");
}
It compiles fine, but the call to it in my Initialize.cpp file
Code:
MarketView::Form1::AddDate("abs",1);
Gives error C2352: 'MarketView::Form1::AddDate' : illegal call of non-static member function
OK, so I change "void AddDate" to "static void AddDate" and now get the error that "static member functions do not have 'this' pointers" so I go back to the "MarketView::Form1::comboBox1" situation where there is no legal syntax after "Box1 to get me to Items->Add
I've been an old fashion programmer for over 47 years. It seems as is the concept of programming computers has changed from the concepts of logic to memorization of complex syntax.
There has to be a simple answer to do this other than to write thousands of lines of code in one Form1.h file. I refuse to believe that the new programming concepts will not allow you to write code in smaller more manageable modules.
What is the proper syntax for breaking up the larger file into more manageable chucks?
unsigned char key[32];
139 unsigned char rfseed[32];
173 f = fopen("/dev/urandom","rb");
174 fread(key,1,32,f);
175 fread(rfseed,1,32,f);
I am having problems copying outputs of the above code into other unsigned char other[32]. I need to keep the output of dev/urandom for backup. But, when I try to assign the values by memcpy(other, key, 32), the values do not match. The same problem happens by assigning values index by index in a loop.
changing a 9 digit integer into a new 9 digit integer through simple mathematical operations. For example, I need to change 123456789 into the new digit 456123789. Sometimes I need to change a 9 digit integer into an 8 digit integer. An example is 789062456 into 62789456. I can ONLY use simple mathematical operations (addition, subtraction, multiplication, division and modulo).
View 4 Replies View RelatedComplete the function myitohex so that its converts 8-byte integer to string based hexadecimals.
Ex: printf("0x%s",myitohex(64,hex)); should printout "0x40" on the screen
char *myitohex(uint8_t i, char *result){
???
return result;
}
I wrote:
#include <stdio.h>
#include <stdint.h>
char *myitohex(uint8_t i, char *result){
*result = i + '0';
[Code] ....
0xp gets printed out which is wrong. I think *result = i + '0'; is wrong. What changes should i do on this row ?
I need to convert a string IP to an unsigned int (uint32), but however solutions I've found elsewhere have not worked (such as `atoi`).
When using `(uint32)"54.171.82.217 ";` : [URL] ....
When using `atoi("54.171.82.217");`: [URL] .....
How can I correctly convert the string version of the IP to the uint32 type?
I'm confused about the actual value of 8 bytes for unsigned integers.
The below code suggests the value is 13217906525252912201:
#include <stdio.h>
#include <inttypes.h>
typedef uint64_t byte_int_t;
int main(void){
byte_int_t t;
printf("%" PRIu64 "
", t);
}
./runprogram
13217906525252912201
However, when I use a calculator, I get a different value: 2^64= 1.8446744e+19
So I was wondering is this really 8 bytes? So I try below test and it produces 8, as expected:
#include <stdio.h>
#include <inttypes.h>
typedef uint64_t byte_int_t;
int main(void) {
byte_int_t t;
printf("%u
", sizeof(t));
return 0;
}
So why does C and my calculator provide two different results?
How do I print an unsigned char in c++? E.g.
unsigned char a[100] = "acdef";
wprintf(L"a is %u
", a);
wcout << "a is " << a << endl;
gives
a is 2880488
a is 002BF3E8
and not
a is acdef
a is acdef
??
what is the difference between unsigned char and char?