`CompareModifiedEntry`, as used in

https://github.com/bitcoin/bitcoin/blob/3c098a8aa0780009c11b66b1a5d488a928629ebf/src/miner.h#L97-L112

will trigger a compile-time error in many `const` operations of index #1 of `indexed_modified_transaction_set` because `CompareModifiedEntry::operator()` is not `const`.

Most likely related to:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=224129
{
public:
    bool operator()(const CTxMemPoolEntry& a, const CTxMemPoolEntry& b)
    {
        return a.GetTime() < b.GetTime();
    }
};
class CompareTxMemPoolEntryByAncestorFee
{
public:
    bool operator()(const CTxMemPoolEntry& a, const CTxMemPoolEntry& b)
    {
        double aFees = a.GetModFeesWithAncestors();
        double aSize = a.GetSizeWithAncestors();
        double bFees = b.GetModFeesWithAncestors();
        double bSize = b.GetSizeWithAncestors();
        
        double f1 = aFees * bSize;
        double f2 = aSize * bFees;
        if (f1 == f2) {
            return a.GetTx().GetHash() < b.GetTx().GetHash();
        }
        return f1 > f2;
    }
};
struct descendant_score {};
struct entry_time {};
struct mining_score {};
struct ancestor_score {};
class CBlockPolicyEstimator;