CFD Online Discussion Forums - GeometricField read

Hi
After hour of search and find no solution I'm going to ask this question. There is for sure similar questions in the forum but I didn't find them.
I want to read a GeometricField, say p, from time folders in a loop. Following program works but it's not a good solution of course:

Code:

     label endTimeIndex=std::floor(runTime.endTime().value()/runTime.deltaTValue());

    for (int j=0;j<=endTimeIndex;j++)

    {

        volScalarField p

        (

            IOobject

            (

                 "p",

                 runTime.timeName(),

                 mesh,

                 IOobject::MUST_READ,

                 IOobject::AUTO_WRITE

           ),

           mesh

        );

        

        Info<<runTime.timeName()<<endl;

        Info<<"p:"<<endl<<p<<endl;

        runTime++;

    }

I was looking for an option like p.readFields() or p.readIfPresent() (which are established by constructors of GeometricField) to avoid redefinition of p in each loop. But these members are private and they are not accessible from main. What shall I do?
Thanks