sql_value.h

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/*
  Copyright (c) 2022, 2024, Oracle and/or its affiliates.
 
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  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.
 
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  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
 
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*/
 
#ifndef ROUTING_SQL_VALUE_INCLUDED
#define ROUTING_SQL_VALUE_INCLUDED
 
#include <optional>
#include <string>
 
/**
 * a nullable SQL value.
 *
 * For now, supports NULL and strings.
 *
 * Note: In the future, may switch to std::variant<> or
 * similar to cover more types if needed.
 */
class Value {
 public:
  using value_type = std::optional<std::string>;
 
  Value(value_type v) : value_{std::move(v)} {}
 
  const value_type &value() const & { return value_; }
 
  /**
   * "NULL" or the quoted string.
   */
  std::string to_string() const;
 
 private:
  value_type value_;
};
 
inline bool operator==(const Value &lhs, const Value &rhs) {
  return lhs.value() == rhs.value();
}
 
inline bool operator==(const Value &lhs, const std::string_view &rhs) {
  if (!lhs.value()) return false;
 
  return std::string_view(*(lhs.value())) == rhs;
}
 
inline bool operator!=(const Value &lhs, const Value &rhs) {
  return !(lhs == rhs);
}
 
inline bool operator!=(const Value &lhs, const std::string_view &rhs) {
  return !(lhs == rhs);
}
 
#endif