Code should look like the following:

// Headers

/////////////////////////////////////////////////////////////////////////////
// Name:        dir/Class.h
// Purpose:     What the class is for
// Author:      You
// Modified by: You
// Created:     Wed Feb 28 21:41:10 2007
// Copyright:   ©2007-2008 Ben Boeckel and Nerdy Productions
// Licence:
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License along
//    with this program.  If not, see <http://www.gnu.org/licenses/>.
/////////////////////////////////////////////////////////////////////////////

#ifndef __HEADER__
#define __HEADER__

#ifdef SOME_DEFINE
#define SOME_OTHER_DEFINE
#endif

#include <QList>
#include <cstdlib>
#include "SomeBigClass.h"

namespace Name
{
    class SomeClass : class SomeBigClass
    {
        public:
            SomeClass();
            SomeClass(int v);
            ~SomeClass();
            
            bool setSomeVar(int s = 0);
            
            int getSomeVar();
        private:
            void somePrivateMethod();
            
            int someVar;
            unsigned* somePtr;
            QList<unsigned> someVector;
    };
}

#endif

// Source

/////////////////////////////////////////////////////////////////////////////
// Name:        dir/Class.cpp
// Purpose:     What the class is for
// Author:      You
// Modified by: You
// Created:     Wed Feb 28 21:41:10 2007
// Copyright:   ©2007-2008 Ben Boeckel and Nerdy Productions
// Licence:
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License along
//    with this program.  If not, see <http://www.gnu.org/licenses/>.
/////////////////////////////////////////////////////////////////////////////

#include "Class.h"

Name::SomeClass::SomeClass()
{
    someVar = 3;
    somePtr = new unsigned[3];
    someVector.clear();
}

Name::SomeClass::someClass(int v)
{
    someVar = 2 * v;
    switch (v)
    {
        case 0:
            if ((v == std::rand()) || (std::rand() < std::rand()))
            {
                somePtr = new unsigned[2 * v];
                someVar = 16;
            }
            break;
        case 1:
        case 2:
            if (std::rand() == 23)
                somePtr = new unsigned[12];
            if (std::rand() == 49)
                somePtr = new unsigned[14];
            else
                somePtr = new unsigned[16];
            break;
        default:
            somePtr = new unsigned[v];
            break;
    }
    someVector.clear();
}

Name::SomeClass::~SomeClass()
{
    delete somePtr;
}

bool Name::SomeClass::setSomeVar(int s)
{
    if (canChange)
    {
        someVar = s;
        return true;
    }
    return false;
}

int Name::SomeClass::getSomeVar()
{
    return someVar;
}

void Name::SomeClass::somePrivateMethod()
{
    for (int i = 0; i < someVar; ++i)
        someVar /= 2;
}