cpp/utility/any

The class describes a type-safe container for single values of any copy constructible type.

@1@ An object of class stores an instance of any type that satisfies the constructor requirements or is empty, and this is referred to as the state of the class  object. The stored instance is called the contained object. Two states are equivalent if they are either both empty or if both are not empty and if the contained objects are equivalent.

@2@ The non-member functions provide type-safe access to the contained object.

Implementations are encouraged to avoid dynamic allocations for small objects, but such an optimization may only be applied to types for which std returns.