import type { BufferedSinkWriter, XlsxSink } from './sink';
import type { XlsxSource } from './source';
/**
 * Wrap a Buffer or Uint8Array as an XlsxSource. The underlying bytes are
 * referenced — no copy — so callers must not mutate them while the source is in
 * use.
 */
export declare function fromBuffer(buf: Buffer | Uint8Array): XlsxSource;
/**
 * In-memory Buffer sink. The buffered path concatenates appended chunks into a
 * single allocation when {@link BufferedSinkWriter.finish} resolves; the
 * convenience `result()` returns it as a Node Buffer.
 */
export declare function toBuffer(): XlsxSink & {
    toBytes(): BufferedSinkWriter;
    result(): Buffer;
};