I have two 16-bit shorts (s1 and s2), and I\'m trying to combine them into a single 32-bit integer (i1). According to the spec I\'m dealing with, s1 is the most significant
Try projecting data.second explicite to short type, like:
const utils::int32 combineddata = ((data.first<<16) | ((short)data.second));
edit: I am C# dev, probably the casting in your code language looks different, but idea could be the same.