boat::db Namespace Reference

Classes
struct	kind< T >
struct	catalog
	Uniform access to vector and raster data. More...
struct	command
struct	source
struct	layer
struct	column
struct	index_key
struct	table
struct	bbox
	Spatial filter for row selection. More...
struct	order_key
struct	page
	Pagination filter for row selection. More...
struct	band
struct	raster
struct	rect
struct	id
class	query
struct	rowset
struct	variant
struct	kind
	Maps a C++ type to the database-neutral type name used by boat. More...
struct	kind< std::string >
struct	kind< blob >

Typedefs
using	null = std::monostate
using	variant_base = std::variant<null, int64_t, double, std::string, blob>

Functions
void	read (variant const &in, geometry::ogc99 auto &out)
	Reads WKB from a blob; NULL produces a default-constructed geometry.
void	write (variant &out, geometry::ogc99 auto const &in)
	Serializes an OGC geometry as WKB in a blob.
template<class T> requires requires { read(in, out.emplace()); }
void	read (variant const &in, std::optional< T > &out)
	NULL becomes std::nullopt.
template<class T> requires requires { write(out, *in); }
void	write (variant &out, std::optional< T > const &in)
	std::nullopt becomes NULL.
template<class Clock, class Duration>
void	read (variant const &in, std::chrono::time_point< Clock, Duration > &out)
template<class Clock, class Duration>
void	write (variant &out, std::chrono::time_point< Clock, Duration > in)
	Formats a time point with microsecond precision and no time-zone suffix.
auto &	operator<< (ostream auto &out, rowset const &in)
auto &	operator<< (ostream auto &out, table const &in)
auto &	operator<< (ostream auto &out, raster const &in)
template<class T>
constexpr auto	kinds_as_array ()
	Creates a std::array from kind<Field>::value for each field of T.
template<class T>
table	to_table ()
rowset	to_rowset (std::ranges::input_range auto &&r)
	Converts a range of structures to a rowset.
template<std::convertible_to< variant_base > T>
void	read (variant const &in, T &out)
void	write (variant &out, std::convertible_to< variant_base > auto const &in)
template<class T> requires requires(T val) { read(var, val); }
T	get (variant const &var)
variant	to_variant (auto const &val)

Variables
template<class T>
constexpr auto	view
	Converts a rowset row to a structure.

Typedef Documentation

null

using boat::db::null = std::monostate

variant_base

using boat::db::variant_base = std::variant<null, int64_t, double, std::string, blob>

Function Documentation

get()

template<class T>
requires requires(T val) { read(var, val); }

T boat::db::get

(

variant const &

var

)

kinds_as_array()

template<class T>

auto boat::db::kinds_as_array ( )

constexpr

Creates a std::array from kind<Field>::value for each field of T.

operator<<() [1/3]

auto & boat::db::operator<<	(	ostream auto &	out,
		raster const &	in )

operator<<() [2/3]

auto & boat::db::operator<<	(	ostream auto &	out,
		rowset const &	in )

operator<<() [3/3]

auto & boat::db::operator<<	(	ostream auto &	out,
		table const &	in )

read() [1/4]

void boat::db::read	(	variant const &	in,
		geometry::ogc99 auto &	out )

Reads WKB from a blob; NULL produces a default-constructed geometry.

read() [2/4]

template<class Clock, class Duration>

void boat::db::read	(	variant const &	in,
		std::chrono::time_point< Clock, Duration > &	out )

Parses "YYYY-MM-DD HH:MM:SS[.ffffff]" without a time-zone conversion. NULL is converted to the clock epoch; excess fractional digits are ignored.

read() [3/4]

template<class T>
requires requires { read(in, out.emplace()); }

void boat::db::read	(	variant const &	in,
		std::optional< T > &	out )

NULL becomes std::nullopt.

read() [4/4]

template<std::convertible_to< variant_base > T>

void boat::db::read	(	variant const &	in,
		T &	out )

NULL becomes T{}.

Exceptions

std::bad_variant_access

if the stored type is incompatible with T.

to_rowset()

rowset boat::db::to_rowset

(

std::ranges::input_range auto &&

r

)

Converts a range of structures to a rowset.

to_table()

template<class T>

table boat::db::to_table

(

)

to_variant()

variant boat::db::to_variant

(

auto const &

val

)

write() [1/4]

void boat::db::write	(	variant &	out,
		geometry::ogc99 auto const &	in )

Serializes an OGC geometry as WKB in a blob.

write() [2/4]

template<class Clock, class Duration>

void boat::db::write	(	variant &	out,
		std::chrono::time_point< Clock, Duration >	in )

Formats a time point with microsecond precision and no time-zone suffix.

write() [3/4]

void boat::db::write	(	variant &	out,
		std::convertible_to< variant_base > auto const &	in )

write() [4/4]

template<class T>
requires requires { write(out, *in); }

void boat::db::write	(	variant &	out,
		std::optional< T > const &	in )

std::nullopt becomes NULL.

Variable Documentation

view

template<class T>

auto boat::db::view

constexpr

Initial value:

= std::views::transform([](range_of<variant> auto&& r) {
    T ret;
    auto it = std::ranges::begin(r);
    if constexpr (requires { read(*it, ret); })
        read(*it++, ret);
    else
        boost::pfr::for_each_field(ret, [&](auto& v) { read(*it++, v); });
    check(it == std::ranges::end(r), "out of fields");
    return ret;
})

Converts a rowset row to a structure.