Why does the leveldb DB::Get API use std::string as value type?

Question

I wanna to store key(url) & value(jpg image) in leveldb. As it is said,

Keys and values are arbitrary byte arrays.

how can I use the DB::Get API?

Answer 1

Slice does not own the memory (just points to it), so returning a Slice would mean that the caller should free the memory.

So a type with value semantics is needed.

The natural value for binary array would be std::vector<uint8_t>, as it implies so. But std::string can also be used instead (as you pointed out in your answer), and it is more useful if you expect to read a real string (no casting needed).

The main problem is that the reason is not documented, though.