why you should prefer std::algorithm...

Today i worked on a huge legacy code base when i meet (1x more) the following kind of loop:

std::vector<int> vec;
...
int max_value = 0;
for ( int i=0 ; i<(int)vec.size() ; i++ )
  {
    if (vec[i] > max_value)
    {
      max_value = vec[i];
    }
  }

I was wondering why some developer always try to reinvent the wheel ?

C++ comes with a tons of useful algorithm to do that kind of stuff, and with an explicit name. In example that code can be rewrite with:

#include <algorithm>
...
std::vector<int> vec;
...
int max_value = *std::max_element<std::vector<int>::iterator >(vec.begin(), vec.end());

it's shorter and more explicit...

Note for C++11 users:

auto max_value = *std::max_element<std::vector<int>::iterator >(begin(vec), end(vec));

VS - How To Collapse your Solution Explorer.

You may have notice (or maybe not) that VS'08 often expand the whole Solution Explorer  when you open a solution.

With VS'12 The VS Team added the solution explorer collapse button, but we can add that functionnality to our old VS using a simple VB Macro.

You have to follow some few step and play! 

1. unzip SolutionCollapse.zip (in Users\YOU\Documents\Visual Studio 2008\Projects\VSMacros80 for example)  
2. Open  VS'08 – View – Other windows – Macros Explorer 3)       Dans l’explorateur de macro – Load Macro Project – And select SolutionCollapse  
3. Now in  Tools –Customize  – Keyboard 
1.  in "Show command containing" enter « Collapse », Scroll the results to find "Macros.SolutionCollapse.CollapseAll"
2.  Set a shortcut  (CTRL-M + CTRL-C for example)

Done.

CppCheck VS integration

1st, download and setup CppCheck from http://cppcheck.sourceforge.net/

Next in VS, Open Tools => Extension and Add the following command

argument line: --enable=all --verbose --template=vs "$(ProjectDir)"

Get back and you will see something like that in your Tools menu.

To add a keyboard shortcut, Go to Tools => Customize => click on the "Keyboard" button, "Show commands containing "Tools.Exter", Select the "ExternalCommand1" if you placed "your CppCheck command on the top of the list and define the shortcut you want. For example, i used CTRL+ALT+C.

Now when working on C/C++ Project and source code in VS, just press your shortcut, to see CppCheck message in the "Output" windows. Click on a message to go immediately into the incriminate code.

Good luck.

How to map array into a std::vector and display value.

As C++ user, you may have to check if a given value is allow in your software and if not display the list of allowed values.

To do that job, you can write code based on C++/STL and use as few "if"s, "while"s, "for"s and other builtin constructs as possible. In the following  example, I try to demonstrate 3 things:

1. Init a vector within a array. Note that in the new C++ standard, you can implement that with a single line.
2. Check if a value is in the vector using the 'find' algorithm.
3. Display on stdout or format into a string all values using 'copy'.

#include <vector>
#include <algorithm>
#include <string>
#include <iostream>
#include <sstream>

int _tmain(int argc, _TCHAR* argv[])
{

  int tab[5] = {1,2,3,4,5};
  std::vector<int> test(tab, tab+5);

  int valueForChecking = -1;
  std::cin >> valueForChecking;

  if(std::find(test.begin(), test.end(), valueForChecking) == test.end())
  {  
    std::copy(test.begin(), test.end(), std::ostream_iterator<int>(std::cout," ")); 
    std::cout << std::endl;
  }
  else
    std::cout << "is in" << std::endl;

  //or

  if(std::find(test.begin(), test.end(), valueForChecking) == test.end())
  {
    std::ostringstream s;
    std::copy(test.begin(), test.end(), std::ostream_iterator<int>(s," "));
    std::cout << "string from vector : " << s.str() << std::endl;
  }
  else
    std::cout << "is in" << std::endl;

  return 0;
}

A Simple polymorphism example...

It seems that the term "Polymorphism" is not so clear that it should to some of team member (and sometimes it also a mess to me to understand object design we made !!!)... So every time, every time i will use polymorphism in my own work, i will try to extract a demonstration/example.

Let's start with the following example in which we can show that we can define a function to call the f function of a 'Base' object, but accessing finally the f function implemented by the child....

class A
{
public:
  virtual void f()
  {
    std::cout << "A::f()" <<std::endl;
  }
};

class B : public A
{
public:
  virtual void f()
  {
    std::cout << "B::f()" << std::endl;
  }
};

class AI : public A
{

};

class BI : public B
{

};

void master_f(A& base_ref)
{
  base_ref.f();
}

int _tmain(int argc, _TCHAR* argv[])
{
  AI oAI;
  BI oBI;

  master_f(oAI);
  master_f(oBI);

 return 0;
}