In order to write a recursive lambda function, you must perform the following:

• Define the lambda in a function scope.
• Assign the lambda to an std::function wrapper.
• Capture the std::function object by reference in the lambda in order to call it recursively.

The following are examples of recursive lambdas:

• A recursive Fibonacci lambda expression in the scope of a function that is invoked from the scope where it is defined:

        void sample() 
        { 
          std::function<int(int const)> lfib =  
            [&lfib](int const n) 
            { 
              return n <= 2 ? 1 : lfib(n - 1) + lfib(n - 2); 
            }; 

          auto f10 = lfib(10); 
        }

• A recursive Fibonacci lambda expression returned by a function, that can be invoked from any scope:

        std::function<int(int const)> fib_create() 
        { 
          std::function<int(int const)> f = [](int const n)  
          { 
            std::function<int(int const)> lfib = [&lfib](int n) 
            { 
              return n <= 2 ? 1 : lfib(n - 1) + lfib(n - 2); 
            }; 
            return lfib(n); 
          }; 
          return f; 
        } 

        void sample() 
        { 
          auto lfib = fib_create(); 
          auto f10 = lfib(10); 
        }