id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
12901	time_point.hpp includes <iostream> header	Vyacheslav Lanovets <vyacheslav@…>	viboes	"Inclusion of <iostream> via inclusion chain causes static global variable being linked into every translation unit. It causes numerous atexit() calls at startup and the processing at finish. The reason is the trick used by all major C++ Standard library developers - putting an instance with static visibility somewhere in iostream header.

This is a minor performance issue, but it also hinders investigation of startup and exit defects in an application. When developer sets breakpoint in the atexit in C runtime library, there is a lot of noise from iostream if there are many cpp files in the application.


There are several affected files in boost.chrono that have <iostream> included:

io\duration_io.hpp
io\time_point_units.hpp
process_cpu_clocks.hpp
time_point.hpp

The reason is not very clear. Please, at least include more specific header, like <ostream>, if really needed.
"	Bugs	closed	Boost 1.65.0	chrono	Boost 1.63.0	Problem	fixed