The Big Programming Thread - Page 476

On May 10 2014 08:21 Ottoxlol wrote:
Have been googling and thinking for a couple of hours I can't crack whats wrong with my program. Would make my day if someone could help. Its a simple inventory system where I have to use heterogeneous collection, dynamic memory allocation and classes in C++. I am finished if not for the Save() function that I would use to write my objects out to a file the same way I read them.

For the parent I use:
virtual void Save(fstream &file) {file << thingsformattedinawayineedthem; } ,

for the children:
void Save(fstream &file){file << 'x' ; Camera::Save(file); file << otherthingsformattedinawayineedthem; }

the function that calls for every object to save itself is:
void Saveall(vector<Parent*> inventory,fstream &file){for (unsigned i=0; i<inventory.size(); i++){inventory[i]->Save(file);}

I did almost exactly the same for a Listall function that prints every objects variables and it worked so I think it has to do something with the way I handle the fstream(currently it does nothing to the file)
Bonus question: is there a clear command for files? if not is there an elegant solution to clearing it(txt in this case).

On May 10 2014 08:40 Nesserev wrote:

Well, your explanation isn't very clear to begin with, what's the problem that you have?

EDIT: For your bonus question, when you open a file, it's cleared from all its contents implicitly (unless you tell it to do otherwise). You can choose the mode in which you open it, by adding the right bitflags, like app to append to the file:
http://www.cplusplus.com/reference/fstream/fstream/open/

// fstream::open / fstream::close
#include <fstream>      // std::fstream

int main () {

  std::fstream fs;
  fs.open ("test.txt", std::fstream::in | std::fstream::out | std::fstream::app);

  fs << " more lorem ipsum";

  fs.close();

  return 0;
}

On May 09 2014 10:24 Blisse wrote:


Not supporting it, but what to do when you do have a user using multiple services and you want to combine them all into one person. Do you just treat all the different log-ins as different people? Then that means if that one person logs in to multiple accounts/services to do something, does the person appear as the same person or as different people?

On May 10 2014 08:21 Ottoxlol wrote:
Have been googling and thinking for a couple of hours I can't crack whats wrong with my program. Would make my day if someone could help. Its a simple inventory system where I have to use heterogeneous collection, dynamic memory allocation and classes in C++. I am finished if not for the Save() function that I would use to write my objects out to a file the same way I read them.

For the parent I use:
virtual void Save(fstream &file) {file << thingsformattedinawayineedthem; } ,

for the children:
void Save(fstream &file){file << 'x' ; Camera::Save(file); file << otherthingsformattedinawayineedthem; }

the function that calls for every object to save itself is:
void Saveall(vector<Parent*> inventory,fstream &file){for (unsigned i=0; i<inventory.size(); i++){inventory[i]->Save(file);}

I did almost exactly the same for a Listall function that prints every objects variables and it worked so I think it has to do something with the way I handle the fstream(currently it does nothing to the file)
Bonus question: is there a clear command for files? if not is there an elegant solution to clearing it(txt in this case).

On May 10 2014 08:40 Nesserev wrote:

Well, your explanation isn't very clear to begin with, what's the problem that you have?

EDIT: For your bonus question, when you open a file, it's cleared from all its contents implicitly (unless you tell it to do otherwise). You can choose the mode in which you open it, by adding the right bitflags, like app to append to the file:
http://www.cplusplus.com/reference/fstream/fstream/open/

// fstream::open / fstream::close
#include <fstream>      // std::fstream

int main () {

  std::fstream fs;
  fs.open ("test.txt", std::fstream::in | std::fstream::out | std::fstream::app);

  fs << " more lorem ipsum";

  fs.close();

  return 0;
}

On May 11 2014 01:12 Invictus wrote:
Hi guys, i'm about to enrol into university for a computer science degree and i have been interested in programming for a really long time. However, i'm just baffled at where to start cause there are just too many languages to learn. I read the OP but there isn't much C learning resources out there(I think?) so I want to try at least picking up C++ or C# first.

Is there any beginning knowledge that I should learn before starting on any language and is there any language that are better for beginners such as me to learn? Thanks very much!

On May 11 2014 02:07 Manit0u wrote:
I think it depends on what you really do with Windows and there are basically 3 options here:
1. Do you play a lot of games? Dual-boot. (Note: we're talking latest AAA titles here for the most part, you can run most games via WINE in Linux and often they even work better than in Windows - Civilization IV & V would be an example of such a case)
2. Do you develop in .NET or otherwise need native Windows stuff (your employer requires MS Office for example)? Dual-boot.
3. Any other case? Get rid of Windows because apart from the above it's a useless piece of crap.

On May 11 2014 02:07 Manit0u wrote:
For starters you can either go newbie-friendly with Linux by picking a distro that has plenty of wizards and is popular (thus a lot of "how do I do xxx in dist yyy?" on the web) like Ubuntu, Crunchbang (for those who like minimalism), openSUSE or go anti-newbie but learn Linux inside-out by picking a distro where you get a very basic setup and have to do everything manually, including kernel recompilation. In the latter case it's important to pick a distro that's very well documented like Arch or Gentoo (Arch is easier since it uses a package manager so you don't have to compile from source).

On May 11 2014 02:07 Manit0u wrote:
I don't think VM is an option for anything past CLI programming since it can get incredibly slow and frustrating.