This is a C++ code for the complex Lambert W function
Use: Make an initial complex number by using the standard C++ library: complex z{ 1.73, 2.118 }; Then call the LambertW function as follows: cout << LambertW(z,k) <<'\n'; to print out the value of W at the point z on the k-th branch. k must be an integer. If k is left out, it is understood to be 0 (principal branch).
The declaration of LambertW reads as complex LambertW(complex z, int k = 0);
Example can be found in the source code.