Efficiently initialise std::set with a sequence of numbers

Question

An obvious (naive?) approach would be:

std::set s;
for (int i = 0; i < SIZE; ++i) {
    s.insert(i);
}

That\'s reasonable rea

Answer 1

This can be accomplished in a single line of code. The lambda capture can initialize the variable i to 0 and the mutable specifier allows i to be updated within the lambda function:

generate_n( inserter( s, s.begin() ), SIZE, [ i=0 ]() mutable { return i++; });