import during;
import std.range : drop, iota;
import std.algorithm : copy, equal, map;

Uring io;
auto res = io.setup();
assert(res >= 0, "Error initializing IO");

SubmissionEntry entry;
entry.opcode = Operation.NOP;
entry.user_data = 1;

// custom operation to allow usage customization
struct MyOp { Operation opcode = Operation.NOP; ulong user_data; }

// chain operations
res = io
    .put(entry) // whole entry as defined by io_uring
    .put(MyOp(Operation.NOP, 2)) // custom op that would be filled over submission queue entry
    .putWith!((ref SubmissionEntry e) // own function to directly fill entry in a queue
        {
            e.prepNop();
            e.user_data = 42;
        })
    .submit(1); // submit operations and wait for at least 1 completed

assert(res == 3); // 3 operations were submitted to the submission queue
assert(!io.empty); // at least one operation has been completed
assert(io.front.user_data == 1);
io.popFront(); // drop it from the completion queue

// wait for and drop rest of the operations
io.wait(2);
io.drop(2);

// use range API to post some operations
iota(0, 16).map!(a => MyOp(Operation.NOP, a)).copy(io);

// submit them and wait for their completion
res = io.submit(16);
assert(res == 16);
assert(io.length == 16); // all operations has completed
assert(io.map!(c => c.user_data).equal(iota(0, 16)));