What do Visual Studio's precompiled headers contain?

I think this article offers the explanation.

Though I cannot say definite thing about the internal of PCH, as for unity builds, even if vector is fully instantiated in PCH, I think unity builds still has some advantage.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.