## Class visitation_result

boost::log::visitation_result — The class represents attribute value visitation result.

## Synopsis

    // In header: <boost/log/attributes/value_visitation.hpp>

    class visitation_result {
    public:

      // Error codes for attribute value visitation.
      enum error_code { ok, value_not_found, value_has_invalid_type };

      // public member functions
      visitation_result(error_code = ok) noexcept;
      explicit operator bool() const noexcept;
      bool operator!() const noexcept;
      error_code code() const noexcept;
    };

## Description

The main purpose of this class is to provide a convenient interface for checking whether the attribute value visitation succeeded or not. It also allows to discover the actual cause of failure, should the operation fail.

### `visitation_result` public member functions

1.     visitation_result(error_code code = ok) noexcept;

   Initializing constructor. Creates the result that is equivalent to the specified error code.

2.     explicit operator bool() const noexcept;

   Checks if the visitation was successful.

   Returns: | `true` if the value was visited successfully, `false` otherwise.

3.     bool operator!() const noexcept;

   Checks if the visitation was unsuccessful.

   Returns: | `false` if the value was visited successfully, `true` otherwise.

4.     error_code code() const noexcept;

   Returns: | The actual result code of value visitation