On: An efficient way to make hash maps with insertion ...

[rob74]

Hash maps are a fairly recent addition to the standard data structures "library", because they are relatively performance-intensive. They are of course very useful and therefore commonplace now, but I think that only came about after the rise of dynamic languages which have built-in hash maps (Javascript objects, PHP "associative arrays" etc.). So nowadays any new programming language which wants to attract web developers (e.g. Go) needs a built-in hash map.

[boardwaalk → rob74]

Ehh, hash tables were invented in the 50s and were and are used wherever they are useful. I’m pretty sure a running joke is that every decently sized C program contains a half dozen hash table implementations. They’re not recent.

[mypalmike → rob74]

Hash maps have been commonly used in C since just about forever.

"isn't a insertion order hash map, basically just a list?"

No. They are different in the computational complexity of random access operations.

[benibela → mypalmike]

But the standard C++ std::unordered_map only came with C++11