`RMACXX_Subarray_t` not being obeyed

[MMukundi]

Reproduction:

int main(){
    // -- SNIP --
    win.fill(1);

    // create a vector, initially 0s
    std::vector<int> a(10); 
    int *abuf = a.data();
    
    // create subarray type
    // Note: Output is unchanged by changes to these values
    rmacxx::RMACXX_Subarray_t<int> foo({1},{2},{10}); 
    
    // put
    win(1,{0},{9}) << foo(abuf);
    win.flush(1);
    std::vector<int> results(10); 
    win(1,{0},{9}) >> results.data();
    win.flush(1);
    // -- SNIP --
}

Expected behavior:

a = { 0, 0, 1, 1, 1, 1, 1, 1, 1, 1};

Observed behavior:

// Note: Output is unchanged by values of subarray_t
a = { 0, 1, 1, 1, 1, 1, 1, 1, 1, 1};

Suspected cause:
include/rmacxx-mpi-rma.hpp

       #define RMACXX_BULK_PUT_NC(origin)\
194|        do{\
...|            /* -- SNIP */\
222|            MPI_Accumulate(origin.ptr_, 1, origin.dtype_, target_, \
223|              /*disp*/ 0, 1, sarr_type, MPI_REPLACE, win_); \
...|            /* -- SNIP */\
265|        }while(0)

No members of the RMACXX_Subarray_t origin, not even the MPI_Subarray_t that was already created, are included in the actual MPI_Accumulate call, likely meaning that all calls are relying on the exact same implementation, regardless of user inputs

[sg0]

Note, like my previous comment win(1,{0},{9}) << foo(abuf); is invoked by as many processes as you are running the program with. So, flushing only for process #1 (which translates to: "complete all outstanding RMA operations from my process to process #1") is erroneous before accessing the window, because the other process is also invoking the same statement and may not be done (in this case, flush is a safe option, which translates to flush_all, meaning: "complete all outstanding RMA operations from my process to all other processes").

[sg0]

Any comments? Is this a bug or a misunderstanding?