I am looking for the correct syntax to typecast a character array as an int. So I would be able to do something like this:
char ch[4]; //...Read characters from file into ch or something, etc... int i = ( int ) &ch;
or
char ch[4]; //...Read characters from file into ch or something, etc... int i; strncpy ( ( char* ) &i, ch, 4 )
I want all the 4 characters ( or bytes ) of ch to be classed as an int. So we are taking the 4 bytes of the character array and placing them in 4 bytes of the integer? How would i go about this?
I am checking to see if two references are bound to the same object. My instincts tell Me, "Check their addresses. If they match, they are bound to the same." At the same time, I have not found anything in the C++ standard which would support this approach. Am I missing something? Is there wording which backs up My instincts? Is there a standard function to do this?
I've been working on a project that involves storing pointers to dynamically allocated class objects in an STL list, but trying to run it something's going wrong.
But it seems like that has a memory leak. Does pop_front() just call the destructor for the object, or will it delete a dynamically allocated chunk of memory? If not, how can I do that deletion to avoid a memory leak?
Im trying to create a function that searches my array for a specific string, and then displays that string and the other content associated with it. I'm basically searching for a keyword within an array that has multiple strings with in each element.
I need to create function Sum() that calculates sum between two containers. Code below work fine except function Sum between two containers...
How I should re - write my code that everything work fine.
Condition of exercise is : "Also create a Sum() function that calculates the sum between two iterators. The function then uses the template argument for the iterator type and accepts two iterators, the start- and end iterator"
1>------ Build started: Project: HP2_ex2_iter, Configuration: Debug Win32 ------ 1> main.cpp 1>c:all myс++ha level 7solutionlevel 7 homework overview of the standard template libraryhp2_ex2_itermain.cpp(47): error C2275: 'C1' : illegal use of this type as an expression
So i made an STL compatible container.And to make this work I had to make my own iterator (derived from std::iterator).
What is the portable (if any) and "well behaved" thing to do in case of usage anomalies.such as iterating an iterator too far, or passing an invalid index to a operator[]
Looking at how VC++ does things in something like std::array or std::vector.
Code:
iterator_type& operator+=(difference_type offset) {// increment by integer #if _ITERATOR_DEBUG_LEVEL == 2 if (size < index + offset) {// report error
[Code] .....
lots of names starting with underscores, so it's implementation specific. Is there even a "well behaved" thing to do ? Or is any such work always going to be compiler specific?
where num1 and num2 are arbitrary numbers. and Terrain is the class of objects I'm trying to store.
I want to be able to use push_back on both the main vector and the vectors within the mapArray vector but I'm unsure of how to target the inner vectors with push_back. How to dynamically store a 2D array of objects.
I am looking for direction on what topic I should be reading up on. I am new to C++ and Windows MFC.
This is my real world problem, in the context of the application user. (these term do not refer to OPP concepts)
I want to create shapes (containers) in an application that will respond and collect other objects;
Imagine a Windows frame, containing several 2 dimensional squares. I want to be able to drag and drop marbles into the squares,and have the square retain and display the marbles in the square, in the order that they were dropped in.
How do I create the shapes, and how will the square sense when a marble is over it?
How would I create irregular shapes (a combination of lines and curves) that would be responsive to the marbles?
Suppose I'm writing a program designed to simulate a large company. I'm interested in tracking each company employee by the location where they work. This company has perhaps a thousand different locations:
class Employee { public: AccessorFunction1(); // does something AccessorFunction2(); // does something different AccessorFunction3(); // does something completely different protected: // Some data
[code]....
Once employees are created and pointers to them are saved in the proper Location vector, I write an accessor function, OrganizeLocation(), designed to do a number of operations on a given vector. The problem is, I have maybe a thousand vectors. How do I call this function and specify which vector I want?
Currently, I'm using this clunky solution:
void Company::OrganizeLocation(int a){ switch(a) { case 1: { for(unsigned int i=0; i<LocationA.size(); i++) { LocationA[i]->AccessorFunction1(); LocationA[i]->AccessorFunction2(); LocationA[i]->AccessorFunction3();
[code]....
The key point here is that whichever vector I choose to operate upon, I'll do the exact same procedure every time. I hate this solution because it results in very long and repetitive code not to mention its very error-prone when you re-editing all those "LocationA 's into "LocationB/C/D/etc."
Or, if it can't be done in C++, is there a better design approach? Ultimately I need the Company object to hold multiple vectors but use one compact accessor function to perform operations on just one of them.
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.
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?
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.
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:
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 ....
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.
