[MESOS-4183] Move operator<< definitions to .cpp files and include <iosfwd> in .hpp where possible.

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.27.0
• Component/s: build
• Labels: mesosphere
• Epic Link: Improve build time
• Sprint: Mesosphere Sprint 25
• Story Points: 3
• Assignee: Alex R
• Reporter: Alex R
• Shepherd: Michael Park
• Created: 16/Dec/15 15:37
• Updated: 29/Apr/19 09:27
• Resolved: 26/Nov/18 12:22

Description

We often include complex headers like <ostream> in ".hpp" files to define operator<<() inline (e.g. "mesos/authorizer/authorizer.hpp"). Instead, we can move definitions to corresponding ".cpp" files and replace stream headers with iosfwd, for example, this is partially done for URI in "mesos/uri/uri.hpp".