swap
Declared in <folly/Expected.h>
<folly/Expected.h>
void swap(Expected& that) noexcept(/* see-below */);
This function is potentially-throwing unless std::is_nothrow_swappable_v<Value> && std::is_nothrow_swappable_v<Error>.
std::is_nothrow_swappable_v<Value> && std::is_nothrow_swappable_v<Error>