Struct template stream_placeholder

Boost C++ Libraries

Struct template stream_placeholder

boost::log::formatters::stream_placeholder — A placeholder class to represent a stream in lambda expressions of formatters.

Synopsis

// In header: <boost/log/formatters/stream.hpp>

template<typename CharT> 
struct stream_placeholder {

  // public member functions
  template<typename T> unspecified operator<<(T const &) const;

  // public data members
  static const stream_placeholder instance;
};

Description

The stream_placeholder class template is a hook that allows to construct formatters from streaming lambda expressions.

`stream_placeholder` public member functions

```
template<typename T> unspecified operator<<(T const & fmt) const;
```
Trap operator to begin building the lambda expression

Parameters:

fmt
Either a formatter or an object to be wrapped into a formatter