Value Class Reference

Value object can store value of scalar type, string, array or document. More...

Public Types
enum	Type {   VNULL , UINT64 , INT64 , FLOAT ,   DOUBLE , BOOL , STRING , DOCUMENT ,   RAW , ARRAY }
	Possible types of values. More...

Public Member Functions
Value Constructors
	Value ()
	Constructs Null value.
	Value (std::nullptr_t)
	Constructs Null value.
	Value (const mysqlx::string &str)
	Constructs Null value.
	Value (mysqlx::string &&str)
	Constructs Null value.
	Value (const std::string &str)
	Constructs Null value.
	Value (std::string &&str)
	Constructs Null value.
	Value (const char *str)
	Constructs Null value.
template<typename C >
	Value (const std::basic_string< C > &str)
	Constructs Null value.
template<typename C >
	Value (const C *str)
	Constructs Null value.
	Value (const bytes &)
	Constructs Null value.
	Value (int64_t)
	Constructs Null value.
	Value (uint64_t)
	Constructs Null value.
	Value (float)
	Constructs Null value.
	Value (double)
	Constructs Null value.
	Value (bool)
	Constructs Null value.
	Value (const DbDoc &doc)
	Constructs Null value.
	Value (const std::initializer_list< Value > &list)
	Constructs Null value.
template<typename Iterator >
	Value (Iterator begin_, Iterator end_)
	Constructs Null value.

Conversion to C++ Types
Attempt to convert value of non-compatible type throws an error.
typedef std::vector< Value >	Array
	Return type of the value stored in this instance (or VNULL if no value is stored).
enum mysqlx::abi2::r0::Value:: { ... }	m_type = VAL
	Return type of the value stored in this instance (or VNULL if no value is stored).
DbDoc	m_doc
	Return type of the value stored in this instance (or VNULL if no value is stored).
std::shared_ptr< Array >	m_arr
	Return type of the value stored in this instance (or VNULL if no value is stored).
friend	SessionSettings
	Return type of the value stored in this instance (or VNULL if no value is stored).
friend	DbDoc
	Return type of the value stored in this instance (or VNULL if no value is stored).
friend	Access
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator int () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator unsigned () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator int64_t () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator uint64_t () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator float () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator double () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator bool () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator mysqlx::string () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator std::string () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
template<typename C >
	operator std::basic_string< C > () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator bytes () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
	operator DbDoc () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
template<typename T >
T	get () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
bytes	getRawBytes () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
Type	getType () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
bool	isNull () const
	Convenience method for checking if value is null.
bool	hasField (const Field &) const
	Check if document value contains given (top-level) field. More...
const Value &	operator[] (const Field &) const
	If this value is not a document, throws error. More...
const Value &	operator[] (const char *name) const
	Return type of the value stored in this instance (or VNULL if no value is stored).
const Value &	operator[] (const mysqlx::string &name) const
	Return type of the value stored in this instance (or VNULL if no value is stored).
iterator	begin ()
	Access to elements of an array value. More...
const_iterator	begin () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
iterator	end ()
	Return type of the value stored in this instance (or VNULL if no value is stored).
const_iterator	end () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
size_t	elementCount () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
const Value &	operator[] (unsigned) const
	Return type of the value stored in this instance (or VNULL if no value is stored).
const Value &	operator[] (int pos) const
	Return type of the value stored in this instance (or VNULL if no value is stored).
void	print (std::ostream &out) const
	Print the value to a stream.
void	check_type (Type t) const
	Return type of the value stored in this instance (or VNULL if no value is stored).
bool	is_expr () const
	Return type of the value stored in this instance (or VNULL if no value is stored).
void	set_as_expr ()
	Return type of the value stored in this instance (or VNULL if no value is stored).

Detailed Description

Value object can store value of scalar type, string, array or document.

Implicit conversions to and from corresponding C++ types are defined. If conversion to wrong type is attempted, an error is thrown. If Value object holds an array or document, then array elements or fields of the document can be accessed using operator[]. Array values can be used as STL containers.

Only direct conversions of stored value to the corresponding C++ type are supported. There are no implicit number->string conversions etc.

Values of type RAW can refer to a region of memory containing raw bytes. Such values are created from bytes and can by casted to bytes type.

Note

Value object copies the values it stores. Thus, after storing value in Value object, the original value can be destroyed without invalidating the copy. This includes RAW Values which hold a copy of bytes.

Member Enumeration Documentation

Type

enum Type

Possible types of values.

See also

getType()

Enumerator
VNULL	Null value.
UINT64	Unsigned integer.
INT64	Signed integer.
FLOAT	Float number.
DOUBLE	Double number.
BOOL	Boolean.
STRING	String.
DOCUMENT	Document.
RAW	Raw bytes.
ARRAY	Array of values.

Member Function Documentation

hasField()

bool hasField ( const Field &  fld ) const

inline

Check if document value contains given (top-level) field.

Throws error if this is not a document value.

operator[]()

const Value & operator[] ( const Field &  fld ) const

inline

If this value is not a document, throws error.

Otherwise returns value of given field of the document.

begin()

Value::iterator begin ( )

inline

Access to elements of an array value.

If non-array value is accessed like an array, an error is thrown.

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

• include/mysqlx/devapi/document.h