We have a very powerful concurrency mechanism but no support for physical parallelism yet. What this means is that it is easy to write programs containing many things that seem like they're happening simultaneously (eg. video games and multi-user web servers), but you don't get a speed boost for having multiple processors yet.
The standard library currently only provides basic IO, primitive types and collections. We will be attaching a gui library, opengl library, networking library, and regex library soon.
Every not open addressed hash table can use load factors up to 100%, compared to 50-75%.
Robin hood is a special case.
Concurrent leapfrog hashing would save the go lock and performance problems better. No need for trees when you can use a proper concurrent in-memory hash table.
And you can use string keys.
Seriously, if you care about lock-free algorithms, zero-cost abstractions, control of memory management and avoiding false sharing, why use Go in the first place? C/C++ and Rust are much more practical choices, even Java has mature concurrent data structures.
IMHO, Go is a sensible choice to achieve 80/100 raw performance. Beyond that, Go is just not the right tool.
