On Sun, 2019-07-07 at 20:31 +0100, Jonathan Wakely wrote: > > It might be useful to at least discuss this in the > > docs, although I suppose systems using glibc <2.17 are getting more > > rare every day. > > There are performance penalties to using it too, so it's not just a > case of saying "hey, you should use this!" > > If you link to librt on GNU/Linux then you get a dependency on > libpthread which causes libstdc++ to always assume your program is > multithreaded, and use atomic ops for reference counting even in > single-threaded programs. Yes, that information is presented in the docs, which is good. But I think the other side of this (that selecting "rt" on older glibc implementations will give a 22-24% performance increase when calling steady_clock() / system_clock()) should also be mentioned. Unless you're building for a very specific target/need, you likely will want your compiler to be able to be able to create multi-threaded programs. Cheers!
