Why was std::swap moved to ?

Question

Why has std::swap been moved to the header for C++11?

N3290 C.2.7 says:

17.6.3.2

Effect on

Answer 1

The committee wanted to allow you to use swap() without introducing a compile-time dependency on the large and more complex header file. Because swap() is so widely used, it makes sense to let you pull in its definition with as little additional baggage as possible; this will generally lead to faster compile times for files that don't otherwise need . Its new home allows it to be used without introducing unneeded overhead.