method_col< _TM > Class Template Reference
[Classes and types for external use]
external name for computed columns
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#include <vdbl_col.h>
Public Types | |
| typedef _TM::return_type | return_type |
return_type is the type of object stored | |
Public Member Functions | |
| _Self * | new_copy () const |
| virtual void | setcontext (const context *_c, const _VDBL_row *_r) |
| 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 |
| std::ostream & | print_contents (std::ostream &o) const |
| virtual const std::type_info & | return_type_id () const |
Detailed Description
template<class _TM>
class method_col< _TM >
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 630 of file vdbl_col.h.
Member Function Documentation
| virtual void _VDBL_colbase< _TM::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 210 of file vdbl_col.h.
| void _VDBL_mthdcol< _TM::context , _TM , _TM::return_type >::def_copy | ( | return_type *& | d | ) | const [inline, virtual, inherited] |
| virtual void _VDBL_colbase< _TM::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 197 of file vdbl_col.h.
| _Self* _VDBL_mthdcol< _TM::context , _TM , _TM::return_type >::new_copy | ( | ) | const [inline, virtual, inherited] |
new_copy is the clone operation for copy-constructor overloading. setcontext sets the context for value retrieval.
Reimplemented from _VDBL_colbase< _TM::return_type >.
Definition at line 534 of file vdbl_col.h.
| std::ostream& _VDBL_mthdcol< _TM::context , _TM , _TM::return_type >::print_contents | ( | std::ostream & | o | ) | const [inline, virtual, inherited] |
This function is needed for the operator<< for columns of type return_type.
Reimplemented from _VDBL_colbase< _TM::return_type >.
Definition at line 561 of file vdbl_col.h.
| virtual const std::type_info& _VDBL_colbase< _TM::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 221 of file vdbl_col.h.
| virtual void _VDBL_mthdcol< _TM::context , _TM , _TM::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 540 of file vdbl_col.h.
The documentation for this class was generated from the following file:
