What is the preferred/idiomatic way to insert into a map?

Question

I have identified four different ways of inserting elements into a std::map:

std::map function;

function[0] = 42;
function.inse         


        

Answer 1

If you want to overwrite the element with key 0

function[0] = 42;

Otherwise:

function.insert(std::make_pair(0, 42));