class A {
private:
   QFile file;

public:
   A::A(QFile file): file(file) {}

   void doSomething() {
      file.open(QIODevice::WriteOnly);
      // ... do operations that can throw an exception
      file.close();
   }
}

class A {
private:
   QFile file;

public:
   A::A(QFile file): file(file) {}

   void doSomething() {
      file.open(QIODevice::WriteOnly);
      try {
          // ... do operations that can throw an exception
      }
      finally {
          file.close();
      }
   }
}

void A::doSomething()
{
    QFile file;
    file.open(...);
    //  ...
    file.close();   //  So you can check that everything when right.
}

class QFileWrapper
{
    QFile* myFile;
public:
    QFileWrapper( QFile* file ) : myFile( file ) {}
    ~QFileWrapper() { myFile->close(); }
};

try {
    /*do something that may throw an exception*/
} catch (.../*the ellipsis means catch anything*/){
    /* any cleanup */
    throw; /*this rethrows the exception, not compulsory to include*/
}