[pjc50]

Sure, if your structure doesn't contain any pointers and you only ever want to support one endianness and you trust your compiler to fix the machine layout of the struct forever.

[zadikian]

Mainly the first thing. If your struct is already serial, of course serialization will be easy.

[userbinator]

...which is true for 99.999% of the time anyway, so it's not worth worrying about.