What is boost::any  :

boost::any is a class from Boost::any Library. It provides the ability to store arbitrary information in a variable in C++.

What to include :

Header File – “boost/any.hpp”.

What can be stored in boost::any :

Anything that is copy constructable like,

  • Built-in data types i.e. int, char, bool and std::string etc.
  • User defined data types that has copy constructor.

How to convert back from boost::any to other type :

To convert boost::any to any other type boost::any_cast is used.

What if casted into wrong type :

It will cause boost::bad_any_cast exception,
For Example,

How to avoid boost::bad_any_cast but still check wrong typecasting :

If actual value of variable inside boost::any is not matched with casting parameter then it will return error.

Useful member functions :

1.)  empty():

Tells if variable is empty or not. Return type is bool.

2.)  type():

Returns the std::type_info, that cab be used to fetch the type information of the value it contains.

When not to use boost::any :

In time critical code because it internally uses RTTI, whis is slow.

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