Today I was solving a problem with bitset which needs to find the first set bit (bit with value 1/true). I looked up in C++ Reference but was not able to find a proper function.

Some one else told me that ._Find_First() works (also mentioned in this blog), which is not documented.

I was curious about if there are more undocumented member functions, so I took a look at the source code and found this:

I think the last question is so funny lol