Type Definition mtbl::MergeFn

type MergeFn = Fn(&[u8], &[u8], &[u8]) -> Vec<u8>;

An MTBL merging function: given a key and two values for that key, create a merged value for that key.

Note that, according to the Rust documentation, such functions should not panic, because such functions are called from C code via the FFI (Foreign Function Interface).