Boost C++ Libraries

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Class template basic_direct_mapping

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

Synopsis

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

template<typename MappedT, typename AttributeValueT = int> 
class basic_direct_mapping :
  public boost::log::sinks::basic_mapping< MappedT >
{
public:
  // types
  typedef AttributeValueT        attribute_value_type;  // Attribute contained value type. 
  typedef base_type::mapped_type mapped_type;           // Mapped value type. 

  // public member functions
  explicit basic_direct_mapping(attribute_name const &, mapped_type const &);
  mapped_type operator()(record_view 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 member functions

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

Constructor

Parameters:

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

```
mapped_type operator()(record_view const & rec) const;
```
Extraction operator

Parameters:

rec

A log record to extract value from

Returns:

An extracted attribute value