C :: Associtivity Of Operators
Jun 17, 2014The + operator has left to right associativity then for the program f1() + f2(), why f1() is not called first compared to f2()?
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C++ :: Using Logical Operators Like And Or
Dec 20, 2013I wrote this program using an online compiler i am getting a lot of errors.
#include <iostream>
#include <string>
#include <sstream>
using namespace std;
int main() {
string birthmonth;
string birthday;
[Code] ....
C++ :: Parallel OMP With Many New Operators?
Jul 14, 2012I have a code that uses multi threads using OMP. However, Inside the code I allocate too many memory using "new".
I know that the memory allocation using new must be done in serial. Therefore I am not getting a good performance out of the multi-threaded program.
I thought about allocating a big memory only once, and then advance the pointer every time I need to allocate a small memory.
For example, if I need to allocate chunks of 7 doubles:
Code:
main_memory = new double [10000];
double* x1 = main_memory;
main_memory+= 7;
double* x2 = main_memory;
main_memory+= 7
However, I do not know how to handle the memory deallocation. Beside, this is not thread safe method because main_memory is shared by all threads.
May be there is a boost library that does this, which I am not aware of.
C++ :: Overloading Subscripting Operators?
Nov 7, 2014I have two class GameOfLife and Cell and i want to overload square braket for class GameOfLife."if g is a GameOfLife object, g[10][5] will return the Cell at row 10 and column 5. If there is no such Cells, then it will return a new Cell with position (-1000,- 1000)."
but if g[10][1000] and 1000>cols,then it returns different Cell exp (3,2) How i do control the col ( [row][col] )?
Code: vector<Cell> GameOfLife::operator [](const int row){
vector<Cell> rowCell;
for(int i=0; i<cols; ++i)
{
if( isLive(row,i) )
rowCell.push_back( Cell(row,i) );
else
rowCell.push_back( Cell(-1000,-1000) );
}
return rowCell;
}
C :: Precedence Of Relational Operators
Apr 3, 2013Came across the foll code:
#include<stdio.h>
main() {
int i=4,j=7;
j=j||(printf("you can")&&(i=5));
printf("%d %d",i,j);
}
output: 4 1
Although I am specifying the braces for the && operator so that it gets executed first..Then also the value of i remains 4 only..Why does not it gets changed to 5??Also the printf does not execute??
C :: Operators In Switch Statements?
May 20, 2013Switch case statements are a substitute for long if statements that compare a variable to several "integral" values ("integral" values are simply values that can be expressed as an integer, such as the value of a char).
So does that mean switch statements can only test if variable == value and nothing more, like > < >= <= != etc... ? I tried to make a program to test this and it seems like switch statements are limited to == but I'm not sure, maybe I'm doing something wrong.
This is the program I tried to make to test this:
Code:
#include <stdio.h>
int main () {
int n;
[Code]....
So is it true that switch statements only work with the built in == operator? if that was the case then I would feel rather meh about switch statements.
C++ :: Overloading Comparison Operators For Using In A Set
Oct 30, 2014I have a small piece of code that used the set::insert function on a set of myClass. For that, I need to overload the < and > operators, which I have, but I still get a huge error saying it can't compare.
set<MyClass> mySet;
MyClass myClass
All the class information gets filled in. Then, I try to insert...
mySet.insert(myClass);
bool operator<(MyClass &lhs, MyClass &rhs) {
return lhs.name < rhs.name; //name is a string
}
The error says
...stl_function.h:230:22: error: no match for 'operator<' in '__x < __y'
MyFile.h:80:6: note: candidate is bool operator<(MyClass&, MyClass&)
C++ :: Overriding New And Delete Operators?
Jun 14, 2014I'm experimenting with a custom memory-pool for my application, and I initially planned to override the global new and delete operators to allocate memory in this pool. But since I'm using QT, this will apply to all the QT-related stuff as well. Should I instead just override the new and delete operators per class?
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Apr 27, 2014I have two files NumDays.h and ClientProgram.cpp
clientprogram.cpp basically has the main module below
int main(){
// Initialized UDT object Declarations
NumDays hoursWorked_John; // Instantiate with Default Constructor
NumDays hoursWorked_Sue(36.9); // Instantiate with Initializing Constructor
NumDays hoursUsed_Sue(4.5); // Instantiate with Initializing Constructor
[Code] .....
I can't figure out anything to put in for NumDays.cpp so it's not there.
C++ :: Increment / Decrement Operators
Sep 5, 2014In the following program.
void main() {
int a=1;
cout<<a++<<" "<<++a<<" "<<a++<<endl;
}
If I execute the above program i should get 1 3 3. But I'm getting different values when I executed this program. The values that I get after execution are 3 3 1.
C/C++ :: Overloading Comparison Operators
Aug 28, 2014I made a program that allows the user to enter information of credit cards on an array of size 5, however I need to allow the user to compare the five credit cards with each other and I am having problems with this particular part. I made my bool operator functions for the operator< and the operator> but how to make the user be able to select which cards he wants to compare and how to compare them. My code is the following:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
const int SIZE = 5;
enum OPCIONES {CARGAR=1, ABONAR, NADA};
[Code] ......
C++ :: Why Can't Take The Address Of Operators For Primitives
Apr 3, 2013Why can't I take the address of operators for primitives?
#include <iostream>
#include <string>
int main()
{
{
std::string (&plus)(std::string const&, std::string const&) = &std::operator+;
std::string a ("Hello, "), b("World!");
std::cout << plus(a, b) << std::endl;
[Code]...
[URL]....
I'm using this functionality in a templated class, do I really have to specialize for primitives or use std::enable_if?
C++ :: Templates / Lambdas And Overloaded Operators
Feb 16, 2015What I'm trying to do is create a class for constructing an 'op tree' for parsing infix notation.
I started with a base class that uses a map of lambdas to actually calculate the operations (since they are mostly 1 line functions) of passed in integer or float values.
This base class just uses a templated T type as the lvalue and rvalue. I realized though that if I overload the math operators, +, -, etc.. I could also use the class itself as a type for the lvalue and rvalue. This lead me to think I could easily create the op tree by using Operation class members themselves as operands, which I think makes sense but I'm having some trouble expressing the code.
Heres what I have thus far
Code:
#include <map>
#include <string>
#include <algorithm>
#include <iostream>
namespace Calc {
[Code] .....
Example, if you look at the main() function I create normal operations easily with integer values. I then try to create a "tree" operation that includes 2 sub-operations as it's rvalue and lvalue, that is where I'm having some conceptual problems as far as implementing the code to do that.
C :: Processor Handling Of Bitwise Operators
Mar 6, 2015what order a CPU would process the following arithmetic problem: 5 - (-9) = 14? Would the CPU recognize that the 'minus a minus' combination simply represents 5 + 9, and proceed with that addition, or would the CPU have to first calculate the 2's complement of -9, and then proceed to take the 2's complement of that first result in order to complete the calculation of the addition of the 'double negative'?
View 2 Replies View RelatedC :: Ιnteger Promotions In Bitwise Operators?
Feb 9, 20151.The operands from << and >> may be any of integer type (including char) The integer promotions are performed on both operands the result has the type of the left operand after promotion.
It means that if we have z = x >> y then sizeof(z) == sizeof(x) ?
2. The ~ operator is unary the integer promotions are performed on its operand.
So if I have short int y; and int x=1; y = ~x what is the meaning here?
C++ :: Output Is Printing Twice With Overloaded Operators
Feb 16, 2013I'm having an issue with output, luckily everything else works!! I'm working with Mixed Numbers and operations on them. So, here's the code I'm testing with:
int main() {
Mixed m1(5), m2(1,1,1), m5(2,2,3);
cout << "m1+m2= " << m1+m2 << endl;
cout << "m1 + 10=" << m1+10 << endl;
cout << "m1 - 10=" << m1-10 << endl;
return 0;
}
And here is the output for that code:
File name: fract.h
#ifndef fract_H
#define fract_H
#include <iostream>
using namespace std;
const int DEFAULT_VAL = 0;
[Code] ....
C++ :: Class Template Friend Operators
Sep 19, 2013The code below doesn't compile. Two things to clear up:
1) I know x is going to be garbage.
2) I used the same type name label ElementType.
#include <iostream>
#include <ostream>
template <typename ElementType>
class Example {
[Code] .....
C++ :: Does Polymorphism Affects Operators Overloading?
Nov 24, 2013I must overload [] but at the same time I must use polymorphism. I wonder if using polymorphism affects operators overloading since when I modified the first class by writing "virtual":
virtual void mostrarDatos(char*, char*, char*);
virtual void calcularEdad(int);
So I can do the polymorphism, it affects the part of the code where suppose to do an addition:
s=student1+=student2;
t=student3+=student4;
u=s+=t;
if I do that, it shows some strange numbers instead of the right ones. Here is the complete code:
.h
#ifndef PERSON_H
#define PERSON_H
#include <iostream>
using namespace std;
class persona {
[Code] ......
C++ :: Algorithm For Permutations Of Operands And Operators
Jun 12, 2014I can't seem to figure out the algorithm to find the right permutation(s) of operands and operators.
We basically have a list of 6 unsigned integers. Using arithmetic operations (addition, subtraction, multiplication, division), find the arithmetic expression that evaluates to a target integer.
Example:
myIntegers = {3, 7, 8, 10, 50, 100};
trgtInt = 315;
Solution is (50 + 10) * 7 - 100 - 8 + 3
We also have the following conditions:
1) Each number from the list can be used only once, but does not have to be used. i.e an expression with 5 or less numbers is acceptable
2) Operators can be used multiple times
I am thinking a parenthesis-free notation like Polish or Reverse Polish notation should be used.
C++ :: Using Bitmask Operators - String Bin To Char
Mar 3, 2013So this is the code I have so far which puts a bitmask seperator base on what I choose. My problem is when Im trying to do them in this manner.
1. 0 to 31, with minimum width set to 8, and separating between every 4 digits.
2. 2^0 to 2^16, with minimum width set to 17, separating between every 8 digits.
3. (2^0-1) to (2^16-1) with minimum width set to 16, and no seperation between digits.
I try doing number 2 called "String multyplyByTwo" but seems to be getting errors.
#include<iostream>
#include<string>
using namespace std;
string binToChar( const int n, unsigned minWidth = 8, unsigned sepMask = 0x11111110 ) {
[Code] ....
C++ :: Calling Overloaded Operators In Main
Jan 10, 2013I believe I have the syntax correct but I'm having difficulty calling my overloaded == operator in main (last snip-it of code). Below are several files explaining the code.
Commission.h here is where the friend bool operator == exists and I believe I have it initialized correctly.
#ifndef COMMISSION_H_INCLUDED
#define COMMISSION_H_INCLUDED
using namespace std;
class Commission {
public:
Commission();
Commission(int, double, double, double );
~Commission();
[Code] .....
C/C++ :: Multiply 2 Variables That Go From 0 To 7 - Logical Operators?
Apr 9, 2015#include <iostream>
using namespace std;
int main(){
int polje[8][8];{
for(int i=0;i<8;i++)
for(int j=0;j<8;j++) {
[Code] .....
I don't get any errors,the program works. The problem is that it doesnt work how it should. This is a simple program that multiplies 2 variables(i and j)that go from 0 to 7. The problem I have is with the logical operators,i want the program to skip multiplication with 0 and when the 2 variables are the same value. When i try using only 1 logical operator it work.
C++ :: Difference Between Ofstream And Ostream Operators
Aug 17, 2014I'm trying to overload an operator << so that it prints to a .txt file. Would these two codes basically do the same thing? If so, which one is the more efficient one to use?
ofstream& operator<<(ofstream& fout, const Grid& g);
ostream& operator<<(ostream & out, const Grid& g);
C++ :: Arithmetic Operators For Custom Class?
Oct 3, 2014I have made a custom class matrices class which allows me to add, multiply, subtract (etc.) matrices. I have the following method for multiplication but I get an error that says
'invalid use of 'this' outside of a non-static member function'
How can I refer to the current instance without getting this error.
void operator *(Matrices& matrix2) {
this.multiplyMatrix(matrix2);
}
C/C++ :: Number Conversions Using Bitwise Operators
Feb 13, 2014I have a project assignment for school to write a program that does number conversions using bitwise operators. The premise is that the user enters a number with one of three letter prefixes -- Q1232, O6322, H762FA, etc. -- and the program will take that number and convert it to the other two number bases. Q is for quarternary, O is for octal, and H is for hexadecimal. The transformations should be done using bitwise operators and bit shifting. I am guessing I need to scan the number, convert it to binary, then convert it to the other two bases.
However, I am completely new to bitwise operators and bit shifting, so how to convert numbers of different bases to binary and then binary to other bases using these bit and bitwise functions. I don't have much code done yet, since I am still unsure of how to approach it, but I'll post what little I have.
Here it is:
#include <stdio.h>
#include <string.h>
int main() {
char numType;
printf("
The user will enter a number up to 32 digits in quarternary
");
printf("(base 4), octal (base 8), or hexadecimal (base 16). If in
");
[Code] ....
I figure in each case I can write a function that converts the entered number to binary, then maybe two more functions that convert said binary number to the other bases. For default in the switch I will tell the user they entered an invalid number. I don't have the program looping until the user types 'EXIT' yet, but I will once I figure out anything about these bitwise operators.
C/C++ :: Define Math Operators As Variable?
Aug 17, 2014I have to create a program that read two numbers and the math operators +, -, * and /. After that I should print the operation required. But I tried to declare a <symbol> variable as char type, without sucess...
Here goes my script:
float num1, num2, result;
char symbol;
printf("Write two numbers:
");
[code]....