Merge multiple sets elements in a single set

Question

I would like to know if there is any std library or boost tool to easily merge the contents of multiple sets into a single one.

In my case I have some sets of ints w

Answer 1

Looks like you are asking for std::set_union.

Example:

#include 
#include 

std::set s1; 
std::set s2; 
std::set s3;

// Fill s1 and s2 

std::set_union(std::begin(s1), std::end(s1),
               std::begin(s2), std::end(s2),                  
               std::inserter(s3, std::begin(s3)));

// s3 now contains the union of s1 and s2