export type BufferLike = Buffer | Uint8Array;
/**
 * Asserts that a buffer-like value has exactly the expected byte length.
 *
 * @param buffer - The {@link Buffer} or {@link Uint8Array} to validate.
 * @param expectedSize - The required length, in bytes.
 * @throws {Error} If `buffer` does not expose a numeric `length` property.
 * @throws {Error} If `buffer.length` does not equal `expectedSize`.
 *
 * @example
 * ```ts
 * assertBufferSize(sha256HashBuffer("hello"), 32); // ok
 * assertBufferSize(Buffer.alloc(16), 32); // throws: "Buffer size mismatch: expected 32, got 16"
 * ```
 */
export declare function assertBufferSize(buffer: BufferLike, expectedSize: number): void;