lately I've been using golang a lot for competitive programming, sometimes uses ruby (because of their awesome built-in combinatorial/permutation/prime/automatic-bignumber library). It would be nice if I could fully ditch C++ (especially the lower_bound/upper_bound/next_permutation function) by having Go implement those functions inside standard library as go 2.0 released, something like this:

// same as C++ STL's lower_bound, upper_bound
pos := slice.LowerBound(arr interface{},cmpFunc func(a,b int)int) // cmpFunc returns -1, 0 or +1
pos := slice.UpperBound(arr interface{},cmpFunc func(a,b int)int)

// similar to lower_bound, upper_bound but return nearest value from sorted slice, eg.
// for example: [1,4,5,6,10] 
// when finding 3 NearestLowerBound = 0 (value=1) NearestUpperBound = 1 (value=4)
// when finding 9 NearestLowerBound = 4 (value=6) NearestUpperBound = 5 (value=10)
pos := slice.NearestLowerBound(arr interface{},cmpFunc func(a,b int)int)
pos := slice.NearestUpperBound(arr interface{},cmpFunc func(a,b int)int)

// same as C++ STL's next_permutation
haveNext := slice.NextPermutation(arr sort.Interface) 

this surely will increase Go's adoption and attract more competitive programmers.
Why as Go 2.0, because some of the competitive programming/online judges still using old version of Go, so when they decided to upgrade to Go 2.0, batteries already included:

• HackerRank (1.13 2020-10-03)
• LeetCode (1.13 2020-10-03)
• CodeForces (1.8? 2017-10-28)
• Google CodeJam (1.7.4 2020-10-03)
• CodeChef (1.7.4 2020-10-03)
• Timus (1.14.6 x64 2020-09-02)
• CodeSignal (1.13.4 2020-11-16)