types.hxx

/* Basic type aliases and forward declarations.
 *
 * Copyright (c) 2000-2025, Jeroen T. Vermeulen
 *
 * See COPYING for copyright license.  If you did not receive a file called
 * COPYING with this source code, please notify the distributor of this
 * mistake, or contact the author.
 */
#ifndef PQXX_H_TYPES
#define PQXX_H_TYPES

#if !defined(PQXX_HEADER_PRE)
#  error "Include libpqxx headers as <pqxx/header>, not <pqxx/header.hxx>."
#endif

#include <cstddef>
#include <cstdint>
#include <iterator>

#if defined(PQXX_HAVE_CONCEPTS) && defined(PQXX_HAVE_RANGES)
#  include <ranges>
#endif


namespace pqxx
{
using result_size_type = int;

using result_difference_type = int;

using row_size_type = int;

using row_difference_type = int;

using field_size_type = std::size_t;

using large_object_size_type = int64_t;


// Forward declarations, to help break compilation dependencies.
// These won't necessarily include all classes in libpqxx.
class binarystring;
class connection;
class const_result_iterator;
class const_reverse_result_iterator;
class const_reverse_row_iterator;
class const_row_iterator;
class dbtransaction;
// 9.0: Remove this.
class errorhandler;
class field;
class largeobjectaccess;
class notification_receiver;
struct range_error;
class result;
class row;
class stream_from;
class transaction_base;


enum class format : int
{
  text = 0,
  binary = 1,
};



template<typename TYPE>
using strip_t = std::remove_cv_t<std::remove_reference_t<TYPE>>;


#if defined(PQXX_HAVE_CONCEPTS) && defined(PQXX_HAVE_RANGES)

template<std::ranges::range CONTAINER>
using value_type = strip_t<decltype(*std::begin(std::declval<CONTAINER>()))>;
#else  // PQXX_HAVE_CONCEPTS

template<typename CONTAINER>
using value_type = strip_t<decltype(*std::begin(std::declval<CONTAINER>()))>;
#endif // PQXX_HAVE_CONCEPTS


#if defined(PQXX_HAVE_CONCEPTS) && defined(PQXX_HAVE_RANGES)
template<typename STRING>
concept char_string = std::ranges::contiguous_range<STRING> and
                      std::same_as<strip_t<value_type<STRING>>, char>;

template<typename RANGE>
concept char_strings =
  std::ranges::range<RANGE> and char_string<strip_t<value_type<RANGE>>>;

template<typename DATA>
concept potential_binary =
  std::ranges::contiguous_range<DATA> and (sizeof(value_type<DATA>) == 1);
#endif // PQXX_HAVE_CONCEPTS


// C++20: Retire these compatibility definitions.
#if defined(PQXX_HAVE_CONCEPTS) && defined(PQXX_HAVE_RANGES)


#  define PQXX_RANGE_ARG std::ranges::range


#  define PQXX_CHAR_STRING_ARG pqxx::char_string


#  define PQXX_CHAR_STRINGS_ARG pqxx::char_strings

#else // PQXX_HAVE_CONCEPTS


#  define PQXX_RANGE_ARG typename


#  define PQXX_CHAR_STRING_ARG typename


#  define PQXX_CHAR_STRINGS_ARG typename

#endif // PQXX_HAVE_CONCEPTS


struct from_table_t
{};


struct from_query_t
{};

} // namespace pqxx
#endif