reserve()

template<typename T>

void fl::deque< T >::reserve ( fl::size n )

inline

Definition at line 537 of file deque.h.

                                        {
        if (n <= capacity()) return;
        // Allocate enough chunks behind the current front-offset to hold n total.
        fl::size needed_chunks = (mFrontOffset + n + kChunkSize - 1) / kChunkSize;
        fl::size cur_chunks = used_chunks();
        if (cur_chunks < needed_chunks) {
            fl::size extra = needed_chunks - cur_chunks;
            // Ensure mMap has room for `extra` more chunks past current back.
            fl::size last_used_idx = (mSize == 0) ? mFrontMapIdx : (mFrontMapIdx + used_chunks() - 1);
            if (last_used_idx + extra >= mMapCapacity) {
                grow_map(0, extra);
            }
            // Allocate chunks at the back to cover [front .. front+n).
            fl::size first_new = (mSize == 0) ? mFrontMapIdx : (mFrontMapIdx + cur_chunks);
            for (fl::size i = 0; i < extra; ++i) {
                if (first_new + i >= mMapCapacity) break;
                if (mMap[first_new + i] == nullptr) {
                    mMap[first_new + i] = allocate_chunk();
                }
            }
        }
    }