Helper class for writing visitors to apply to data_t. More...

#include <visitors.hpp>

Public Types
typedef RV	result_type
	The return type from applying this visitor. More...

typedef DERIVED	derived_t
	The type of the derived class. More...

Public Member Functions
result_type	operator() () const
	Visit an empty variant (don't override this, instead override visitEmpty) More...

result_type	visitEmpty () const
	Visit an empty variant. More...

result_type	operator() (int64_t i) const
	Visit an integer (don't override this, instead override visitInteger) More...

result_type	visitInteger (int64_t i) const
	Visit an integer. More...

result_type	operator() (double i) const
	Visit a double (don't override this, instead override visitDouble) More...

result_type	visitDouble (double i) const
	Visit a double. More...

result_type	operator() (bool i) const
	Visit a boolean (don't override this, instead override visitBoolean) More...

result_type	visitBoolean (bool i) const
	Visit a boolean. More...

result_type	operator() (const char *i) const
	Visit a string (don't override this, instead override visitString) More...

result_type	visitString (const char *i) const
	Visit a string. More...

result_type	operator() (const decimal_t &i) const
	Visit a decimal (don't override this, instead override visitDecimal) More...

result_type	visitDecimal (const decimal_t &i) const
	Visit a decimal. More...

result_type	operator() (const buffer_t &i) const
	Visit a byte buffer (don't override this, instead override visitBuffer) More...

result_type	visitBuffer (const buffer_t &i) const
	Visit a byte buffer. More...

result_type	operator() (const list_t &i) const
	Visit a list (don't override this, instead override visitList) More...

result_type	visitList (const list_t &i) const
	Visit a list. More...

result_type	operator() (const map_t &i) const
	Visit a map (don't override this, instead override visitMap) More...

result_type	visitMap (const map_t &i) const
	Visit a map. More...

result_type	operator() (const sag_underlying_custom_t &i) const
	Visit a custom object (don't override this, instead override visitCustom) More...

result_type	visitCustom (const sag_underlying_custom_t &i) const
	Visit a custom object. More...

Protected Member Functions
result_type	error (const std::string &reason) const
	Handles visiting unhandled types. More...

Detailed Description

template<typename DERIVED, typename RV>
class const_visitor< DERIVED, RV >

Helper class for writing visitors to apply to data_t.

This class provides the result_type typedef and all the operator()() methods and should be used for visiting const data_ts. or non-const data_ts that you don't require non-const access to. If you need to modify the data_t contents then use visitor.

These then call to visitTYPE methods which default to an error condition.

Users should override the visitTYPE(const TYPE&) const methods for the types which their visitor needs to handle. Unhandled types will still default to error.

The default error condition is to throw std::runtime_error. If you wish to have a different error condition then override the error() method.

This class is templated over both the derived class (to avoid the need for virtual calls) and the return type. It should be used as:

class my_visitor: public visitor<my_visitor, void> { ... };