I would like to be able to predict what will be in the resulting binary when I call Write in Ada to serialize a record. Do you know where I can look this up?
I have some legacy Ada software that produces a binary file by Write-ing a record, and I need to debug a C++ program that is supposed to write a compatible binary file. So, I would like to understand what rules Ada follows when it serializes a record, so that I can make sure that the C++ code will produce a functionally equivalent record.
As mentioned by others, without additional instruction the compiler will make its own decisions about record layout. The best approach would be to change the original code to write the record using a specific layout. In particular, the record representation clause allows the Ada programmer to specify exactly the physical layout for a record. In fact, you should check to see whether the original code has one of these for the type in question. If it does, then this would answer your question precisely.