Since I am tagged, I will say something.

I am not sure its a good idea to include bits/stdc++, I was told a couple of time that this is not a good practice.
And anyways, using clang++ (the default for this project), it does not compile out of the box:

$ make bubble_sort_demo 
clang++ -g -Wall -Wno-unused-function -o bubble_sort_demo src/bubble_sort_demo.cpp -I./include -I. -lm
In file included from src/bubble_sort_demo.cpp:6:
./include/bubble_sort.h:26:10: fatal error: 'bits/stdc++' file not found
#include <bits/stdc++>
         ^~~~~~~~~~~~~
1 error generated.
make: *** [Makefile:245: bubble_sort_demo] Error 1

Also, src/bubble_sort_demo.cpp will expect the right namespace and function signature here

Do you care to explain what you are trying to achieve ?

Have a nice day :)

From my point of view, it is not an improvement to

• break public contract (the signature changed from alg::BubbleSort(T[], int, int) to std::bubble(X*, int))
• include unknown header so the project does not compile (fatal error: 'bits/stdc++' file not found).

I feel I am missing something here, I will leave let others review this PR.