namespace TFDevice {

// -------------------------------------------------------------------------- //
// ValueConstraint.
// -------------------------------------------------------------------------- //

ValueConstraint Merge(ValueConstraint a, ValueConstraint b) {
  return a > b ? a : b;
}

LogicalResult IsStaticallyResolved(Value value, ValueConstraint constraint) {
  // Resolve constraints inferred from the tensor type.

      if (is_op_a && *result_constraint == ValueConstraint::kShape)
        operands.Insert(op->getOperand(0), ValueConstraint::kRank);

      // `test.OpB` converts value constraint to shape constraint.
      if (*result_constraint == ValueConstraint::kValue)
        operands.Insert(op->getOperand(0), ValueConstraint::kShape);
    }

    return success();
  }
};

// the shape, you always know the rank.
ValueConstraint Merge(ValueConstraint a, ValueConstraint b);

// Returns success if constraint can be resolved statically based on the value
// type, e.g. `shape` constraint can be resolved if the value is a tensor of
// statically known shape.
LogicalResult IsStaticallyResolved(Value value, ValueConstraint constraint);