The following code example is taken from the book
C++ Templates - The Complete Guide, 2nd Edition
by David Vandevoorde, Nicolai M. Josuttis, and Douglas Gregor,
Addison-Wesley, 2017
© Copyright David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor 2017
#include <string>
#include <map>
#include <algorithm>
int main()
{
std::map<std::string,double> coll;
//...
// find the first nonempty string in coll:
auto pos = std::find_if (coll.begin(), coll.end(),
[] (std::string const& s) {
return s != "";
});
}