[anon_q]

Hello,
I have an OpenFOAM code that compiles and runs properly under OpenFOAM 6.
Now I switched to OpenFOAM V1806 but unfortunately the code doesn't compile. After reading the errors reported by the compiler, I understand that the problem is caused by hashtable, so I decided to isolate the problem and I created the sample code below that produces the same error:

The code:

#include "fvCFD.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

void fillHashTable(HashTable<List<label>, label>& hashTable, label maxN);
int main(int argc, char *argv[])
{

    HashTable<List<label>, label> table1;

    fillHashTable(table1, 5);

    Info << table1 << endl;
    Info<< "End\n" << endl;

    return 0;
}

void fillHashTable(HashTable<List<label>, label>& hashTable, label maxN)
{
    List<label> tmpList;
    for(int i=0; i < maxN; ++i)
    {
        tmpList.clear();
        tmpList = {2*i, i*i, i*i*i};
        hashTable.insert(i , tmpList);
    }
}

The error:

...
/home/evren/OpenFOAM/OpenFOAM-v1806/src/OpenFOAM/lnInclude/HashTableI.H:35: error: no match for call to ‘(Foam::string::hash) (const int&)’
     return Hash()(key) & (capacity_ - 1);
            ~~~~~~^~~~~
...

As I stated above, the code compiles and works perfectly when I use OpenFOAM 6.
Could you please help me debug this problem, is it a bug?
Update:
After changing the type of key to word it works, Could you please confirm that hashtables in OpenFOAM v1806 work only with string keys?