In order to test catching exceptions from an initializer list, I deliberately did bad practice by hard coding an argument to a ctor that would cause a std::bad_allocto be thrown. Obviously better practice is to send a variable, but that would cause a compile error, so I hard coded a value.
The program I wrote creates Prime Numbers up to a specified limit which is an argument to the ctor of type std::size_t. The program works fine IMO, using g++ in cygwin:
$ time ./PrimesExe
Limit is 2000000
148933 Primes Created
real 0m1.210s
user 0m1.123s
sys 0m0.046s
Now when I send something invalid like a negative number or something too big for std::size_t, the program seems to run indefinitely, when compiled with g++ under cygwin. I haven't tested it yet on Linux.
However, if I do the same on VS2013 express, it takes about 15 seconds to print the expected caught exception message. I was not expecting it to take so ridiculously long compared to the reasonable amount of work involved in doing primes up to 2 million.
I have read up about what is involved in catching exceptions: stack unwinding, keeping track of what needs to be destroyed etc. But this is 1 object with 1 ctor argument, no Base classes or any other complications. So why such a long or indefinite amount of time?
This whole example is probably contrived, and I am wondering whether exceptions is the right tool for this - it is similar to the divide by zero problem, or could be considered a programming error to call a ctor with a bad argument?
Also, catching an exception thrown by an initalizer list seems a bit awkward in that one seems to have enclose the creation of the object and all subsequent uses of it (and any code in between ) in the same try block, otherwise it goes out scope. I suppose I could try to write a wrapper function that returns a smart pointer reference to a valid object, but I would have to test the validity of it's return too. That's the awkward part - there is probably a better way?
Are there any recommended ways of recovering from initializer list exception, that is, to allow the user to enter a new hopefully valid value and try to create the object again?
#include <iostream> #include <initializer_list> using namespace std; void doSomething(std::initializer_list<int> list) { } int main() { doSomething({2,3,6,8}); return 0; }
I write a small piece of code like above. But I can not compile it successfully. I try it both with and without the line "using namespace std", but nothing worked.
The error list: Symbol 'initializer_list' could not be resolved
What I want is simple: I want to catch a dialog box!
The dialog box pops very frequently in a website. We have to put a username and password and press OK. I checked with spy++. It doesn't have any child windows. So catching the dialog box with windows API is ruled out. It must be a HTML dialog. I have to get DOM COM interfaces of the dialog.
Another option may be to make an add-on to get the interface to IWebBrowser2 and get the events fired. The title of the dialog box is "Authentication Required". If the events will be fired for that dialog box, I can check the title using IHTMLDocument2::get_Title.But will the events be fired for HTML dialog box? How to catch that desturbing dialog box.
Is it possible to develop any application without exceptions? I don't want to try and catch exceptions and remove it.but I want to write codes which should never create exceptions is it possible?
I've been pondering which of these 2 approaches would make for the best interface for a library: Defining custom exceptions with specific names for different error scenarios but with standard behaviour, or simply using the predefined exceptions from the STL.
This is my current approach: Code: namespace rpp { class ConnectionError : public std::exception { public: ConnectionError(const std::string &p_err);
[Code] .....
This seems to make for more descriptive code but it adds no functionality and the implementations are completely identical, which seems "off" to me, somehow.
The task is to use the assignment operator of a class, but change all the data except certain ones. For example, below we are to assign all Person data of 'other' except for 'name' and 'ID':
#include <iostream> #include <string> struct Person { std::string name; int ID, age, height, weight;
[Code] .....
Name = Bob ID = 2047 Age = 38 Height = 183 Weight = 170
Name = Frank ID = 5025 Age = 25 Height = 190 Weight = 205
Bob pretends to be Frank, but keeps his name and ID.
Name = Bob ID = 2047 Age = 25 Height = 190 Weight = 205
But I think the way I did it is pretty lousy (note the wasted steps changing the name and ID only to revert them back? So the ideal solution should require no wasted steps, unlike the method above, and changes to what the exclusions should be should be in only one place (not two like above). Of course, we assume that Person shall have many, many data members (and constantly increasing), so that simply defining Person::operator= (const Person& other) to handle all data except for 'name' and 'ID' is out of the question.
#include <iostream> int ival1 int ival2=1 int summe /* run this program using the console pauser or add your own getch, system("pause") or input loop */ int main() {
I working on an assignment that processes an array of structs. In the main function I am attempting to declare an array of Author structures with 3 elements. It is supposed to be initialized to set all of the string fields (the names and book titles) to "NONE", and the double fields (the prices) to zero. This is supposed to be done in one statement, not using loops. Here is what I have.
//prototype for function to print the content of array on screen void showInfo(Author a[], int size);
[Code] .....
I was under the impression that an array can only hold the values of one data type. So doubles and strings in the same array doesn't make sense to me. However, that's the example my teacher drew up. The error keeps telling me that there are too many initializer values.
Code: extended initializer lists only available with -std=c++11 or -std=gnu++11 that I belive is due to having initialized a class array in the constructor somewhat like this: Code: class xpto { public; xpto():num{25,25}{} int num[2]; };
Since the code I'm developing is not meant to be compiled only by me and I want to ensure there are no incompatibilities with other machines I would like to kow whats the best way to initialize the array that is not c++11 dependent.
Is there no way to do it directly on the constructor "pre-instructions" (don't know the correct designation for the initialization section)? or do I have to put the instructions on the constructor body.
class DataBase { // Change the connection path here to your own version of the database public SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)v11.0;AttachDbFilename=|DataDirectory|UberDatabase.mdf;Integrated Security=True;"); public DataBase() { } }
And in the same namespace as this class I have a form that calls it like so:
DataBase dBase = new DataBase(); SqlCommand trythis = new SqlCommand("Register", dBase.con);
However, I'm getting the field initializer error on dBase.con. I'm not sure why, but when I call the database from another file (program.cs) it works fine this way.
Code: struct _Node { // list node _Genptr _Next; // successor node, or first element if head _Genptr _Prev; // predecessor node, or last element if head _Ty _Myval; // the stored value, unused if head };
The stored value is wasted space for the list head. Is there any advantage to implementing list using the same structure for a list head and node?
// Write a function called insertEntry() to insert a new entry into a linked list.
Have the procedure take as arguments a pointer to the list entry to be inserted (of type struct entry as defined in this chapter), and a pointer to an element in the list after which the new entry is to be inserted.
// The function dveloped in exercise 2 only inserts an element after an existing element in the list, thereby prenting you from inserting a new entry at the front of the list.
(Hint: Think about setting up a special structure to point to the beginning of the list.)
This is a working version of the exercise, but I don't think I'm doing what's asked. I was able to add an element to the beginning of the list using an if statement, not creating a special structure that points to the beginning of the list. How would I go about creating a special structure that points to the beginning of the list to add a new element at the beginning of the list?
I'm trying to display a list of MSMQ messages in a list box based on a drop-down list holding the environment.So i've setup the binding and i know that the list loads but nothing shows up in the list? I should be setting like a display member or something but i'm not entirely sure
I have a linked list comprised of chars like so...
Code:
node1 - "p" node2 - "o" node3 - "p"
I need a function that will take in three perameters...node *replaceChar(node *head, char key, char *str)Stipulations of this function. head is the head of the list, 'key' and 'str' are guaranteed to contain alphanumeric characters only (A-Z, a-z, and 0-9). str can range from 1 to 1023 characters (inclusively). So if I call this function with these perameters..
Code:
node *head == /*the head of the list to be examined*/ char key == "p"char *str == "dog"The new list will look like this... node1 - 'd' node2 - 'o' node3 - 'g' node4 - 'o' node5 - 'd' node6 - 'o' node7 - 'g'
All instances of 'p' were replaced with 'dog' I have a toString function which takes in a string and converts it to a linked list and returns the head. So assume that you can call the function on str = "dog" so...
Code:
toString(str) == /*this will return the head to the list made from the str*/
If it's unclear what my question is...I am stumped on how to write the replaceChar function the one that takes in three perameters..
I want to maintain a list. which will update at regular interval. so I thought to with linked list. Earlier I have used linked list.
Code:
typedef struct { short nwkaddr; unsigned char macaddress[8]; }device_t; }
[code]....
This program is giving many errors. I tried lot to fix it. If I fix one then other bug is arising. for that I did't mentioned what bug i got.Main Issue is while (curr->next->list != NULL) this is giving segmentation fault if i add element second time
