in lib/h3core.js [899:908]
export function cellToChildPos(h3Index, parentRes) {
const [lower, upper] = h3IndexToSplitLong(h3Index);
const childPos = C._malloc(SZ_INT64);
try {
throwIfError(H3.cellToChildPos(lower, upper, parentRes, childPos));
return readInt64AsDoubleFromPointer(childPos);
} finally {
C._free(childPos);
}
}