This version of Boost is under active development. The current version is 1.88.0.
C++
11
Added in Boost
1.30.0
Categories:
Data
A value-semantic, type-safe wrapper for representing 'optional' (or 'nullable') objects of a given type. An optional object may or may not contain a value of the underlying type.
This Release
optional
A library for representing optional (nullable) objects in C++.
optional<int> readInt(); // this function may return either an int or a not-an-int
if (optional<int> oi = readInt()) // did I get a real int
cout << "my int is: " << *oi; // use my int
else
cout << "I have no int";
For more information refer to the documentation provided with this library.