value

A holder for any AMQP value, simple or complex. More...

#include <value.hpp>

Inheritance diagram for value:

Public Member Functions
	value ()
	Create a null value.
template<class T >
	value (const T &x, typename assignable< T >::type *=0)
	Copy from any allowed type T.
template<class T >
assignable< T, value & >::type	operator= (const T &x)
	Assign from any allowed type T.
type_id	type () const
	Get the type ID for the current value.
bool	empty () const
	True if the value is null.
void	clear ()
	Reset the value to null/empty.
Copy a value
	value (const value &)
value &	operator= (const value &)
	value (value &&)
value &	operator= (value &&)

Friends
void	swap (value &, value &)
	swap values
std::ostream &	operator<< (std::ostream &, const value &)
	If contained value is a scalar type T, print using operator<<(T) More...
Comparison operators
bool	operator== (const value &x, const value &y)
bool	operator< (const value &x, const value &y)

Related Functions
(Note that these are not member functions.)
template<class T >
T	get (const value &v)
	Get a contained value of type T. More...
template<class T >
void	get (const value &v, T &x)
	Like get(const value&) but extracts the value to a reference x instead of returning it. More...
template<class T , class U >
void	get (const U &u, T &x)
template<class T >
T	coerce (const value &v)
	Coerce the contained value to type T. More...
template<class T >
void	coerce (const value &v, T &x)
	Like coerce(const value&) but assigns the value to a reference instead of returning it. More...

Detailed Description

A holder for any AMQP value, simple or complex.

See also

AMQP and C++ types

Examples

service_bus.cpp.

Friends And Related Function Documentation

operator<<

std::ostream& operator<< ( std::ostream &  , const value &    )

friend

If contained value is a scalar type T, print using operator<<(T)

Complex types are printed in a non-standard human-readable format but that may change in future so should not be parsed.

get() [1/2]

T get ( const value &  v )

related

Get a contained value of type T.

For example:

 uint64_t i = get<uint64_t>(x)

This will succeed if and only if x contains a uint64_t value.

Exceptions

conversion_error

if contained value is not of type T.

get() [2/2]

void get ( const value &  v, T &  x  )

related

Like get(const value&) but extracts the value to a reference x instead of returning it.

May be more efficient for complex values (arrays, maps, etc.)

coerce() [1/2]

T coerce ( const value &  v )

related

Coerce the contained value to type T.

For example:

 uint64_t i = coerce<uint64_t>(x)

This will succeed if x contains any numeric value, but may lose precision if it contains a float or double value.

Exceptions

conversion_error

if the value cannot be converted to T according to std::is_convertible

coerce() [2/2]

void coerce ( const value &  v, T &  x  )

related

Like coerce(const value&) but assigns the value to a reference instead of returning it.

May be more efficient for complex values (arrays, maps, etc.)

---

The documentation for this class was generated from the following file:

• proton/value.hpp