Class template basic_direct_mapping

Boost C++ Libraries

Class template basic_direct_mapping

boost::log::sinks::basic_direct_mapping — Straightforward mapping.

Synopsis

// In header: <boost/log/sinks/attribute_mapping.hpp>

template<typename CharT, typename MappedT, typename AttributeValueT = int> 
class basic_direct_mapping :
  public boost::log::sinks::basic_mapping< CharT, MappedT >
{
public:
  // types
  typedef AttributeValueT             attribute_value_type;  // Attribute contained value type. 
  typedef base_type::char_type        char_type;             // Char type. 
  typedef base_type::string_type      string_type;           // String type. 
  typedef base_type::values_view_type values_view_type;      // Attribute values view type. 
  typedef base_type::mapped_type      mapped_type;           // Mapped value type. 

  // construct/copy/destruct
  explicit basic_direct_mapping(string_type const &, mapped_type const &);

  // public member functions
  mapped_type operator()(values_view_type const &) const;
};

Description

This type of mapping assumes that attribute with a particular name always provides values that map directly onto the native values. The mapping simply returns the extracted attribute value converted to the native value.

`basic_direct_mapping` public construct/copy/destruct

explicit basic_direct_mapping(string_type const & name, 
                              mapped_type const & default_value);

Constructor

Parameters:

`default_value`	The default native value that is returned if the attribute value is not found
`name`	Attribute name

`basic_direct_mapping` public member functions

```
mapped_type operator()(values_view_type const & values) const;
```
Extraction operator

Parameters:

values
A set of attribute values attached to a logging record

Returns:
An extracted attribute value