Method operator<

src/primitives/bitcoin/transaction.h:37–41

    bool IsNull() const { return (hash.IsNull() && n == NULL_INDEX); }

    friend bool operator<(const COutPoint& a, const COutPoint& b)
    {
        int cmp = a.hash.Compare(b.hash);
        return cmp < 0 || (cmp == 0 && a.n < b.n);
    }

    friend bool operator==(const COutPoint& a, const COutPoint& b)
    {