[cfe-dev] Transforming push_back(T(args, ...)) into emplace_back(args)

[Vedant Kumar via cfe-dev]

Hi all,

It's common to see code which does this:

  (1) V.push_back(T(args, ...));

When it could do this instead:

  (2) V.emplace_back(args, ...);

IIUC, the copy constructor for T is never called in case (2).

Would it be possible/worthwhile/correctness-preserving to perform this transformation in clang? Based on a cursory grep it doesn't seem like we do this today, but I could've missed something.

thanks
vedant