type of the key to write
type of the value to write
type of the key to read, automatic conversion will happen
type of the value to read, automatic conversion will happen
optional, custom code to use for dumping the data. The code is expected to define a variable "header_size" containing the size of the header
Test writing & loading of the given combination of struct types on a virtual file
Depending on the exact combinations, the key structs should offer the following methods:
* compare ( <other_key_struct> * ) - compare the two structs * K old() - convert this struct to the older one
The value structs should offer only a compare function.