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method_col< _M > Class Template Reference
[Classes and types for external use]

external name for computed columns More...

#include <vdbl_col.h>

Inheritance diagram for method_col< _M >:

[legend]Collaboration diagram for method_col< _M >:

[legend]List of all members.

Public Types
typedef _M::return_type	return_type
	return_type is the type of object stored
Public Methods
_Self *	new_copy () const
virtual void	setcontext (const context *_c, const _VDBL_row *_r)
virtual void	setcontext (const context *_c, const _VDBL_row *_r) VDBL_PURE_VIRTUAL virtual void get(return_type &c) const VDBL_PURE_VIRTUAL virtual void def(return_type &d) const VDBL_PURE_VIRTUAL virtual void get_ptr(return_type const *&c) const VDBL_PURE_VIRTUAL virtual void get_copy(return_type *&c) const
void	get (type &c) const
	the function object provides us with the retrieval method
void	get_ptr (type const *&c) const
	there is no way to get a pointer to the method's result properly
void	def (type &d) const
	the default value might be different, and might be computed differently
virtual void	get_copy (_VDBL_alltype_base *&v) const
void	def_copy (return_type *&d) const
virtual void	def_copy (_VDBL_alltype_base *&v) const
virtual const std::type_info &	return_type_id () const

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Detailed Description

template<class _M>
class method_col< _M >

this is the external name of the standard column for methods.

a method can only be used if it provides at least the following

• type definitions: # context specifies the context class for evaluation # return_type specifies the return value type of the evaluation
• methods: # const return_type& operator()() const for evaluation # const return_type& def() const for evaluation of the default value # void setcontext(const context* _c, const _VDBL_row* _r) for setting the evaluation context

usually, a method will be a class derived from the method base class.

Definition at line 631 of file vdbl_col.h.

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Member Function Documentation

virtual void _VDBL_colbase< _M::return_type >::def_copy (  _VDBL_alltype_base *&    v )  const [inline, virtual, inherited]

This version of get_copy returns a copy of the columns default value within an alltype. This is useful for passing on column values. It can also be used to circumvent the strict run-time type checking. The user is, however, DISCOURAGED to do so. Definition at line 209 of file vdbl_col.h.

void _VDBL_mthdcol< _M::context, _M, _M::return_type >::def_copy (  return_type *&    d )  const [inline, virtual, inherited]

This function returns a pointer to a copy of the column's default value. The copy of the value is allocated by new. It has to be deleted by the user to avoid memory leaks. Reimplemented from _VDBL_colbase< _M::return_type >. Definition at line 559 of file vdbl_col.h.

virtual void _VDBL_colbase< _M::return_type >::get_copy (  _VDBL_alltype_base *&    v )  const [inline, virtual, inherited]

This version of get_copy returns a copy of the columns value within an alltype. This is useful for passing on column values. It can also be used to circumvent the strict run-time type checking. The user is, however, DISCOURAGED to do so. Definition at line 196 of file vdbl_col.h.

_Self* _VDBL_mthdcol< _M::context, _M, _M::return_type >::new_copy (    )  const [inline, virtual, inherited]

new_copy is the clone operation for copy-constructor overloading. Reimplemented from _VDBL_colbase< _M::return_type >. Definition at line 535 of file vdbl_col.h.

virtual const std::type_info& _VDBL_colbase< _M::return_type >::return_type_id (    )  const [inline, virtual, inherited]

This function returns the type_info of the column type. This information is used during run-time type checking. Definition at line 220 of file vdbl_col.h.

virtual void _VDBL_colbase< _M::return_type >::setcontext (  const context *    _c, const _VDBL_row *    _r )  const [inline, virtual, inherited]

This function returns a pointer to a copy of the column's value. The copy of the value is allocated by new. It has to be deleted by the user to avoid memory leaks. Definition at line 156 of file vdbl_col.h.

virtual void _VDBL_mthdcol< _M::context, _M, _M::return_type >::setcontext (  const context *    _c, const _VDBL_row *    _r )  [inline, virtual, inherited]

for setting the context, the setcontext method of the function object is used. Definition at line 541 of file vdbl_col.h.

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

• vdbl_col.h

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