mds: build without "using namespace std"

* add "std::" prefix in headers
* add "using" declarations in .cc files.

so we don't rely on "using namespace std" in one or more included
headers.

Signed-off-by: Kefu Chai <kchai@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mds/LogEvent.h b/src/mds/LogEvent.h
index 4e368c97b5e..317b6579fc1 100644
--- a/src/mds/LogEvent.h
+++ b/src/mds/LogEvent.h
@@ -89,7 +89,7 @@ public:
     ENCODE_FINISH(bl);
   }
 
-  virtual void print(ostream& out) const { 
+  virtual void print(std::ostream& out) const {
     out << "event(" << _type << ")";
   }
 
@@ -125,7 +125,7 @@ private:
   LogSegment *_segment = nullptr;
 };
 
-inline ostream& operator<<(ostream& out, const LogEvent &le) {
+inline std::ostream& operator<<(std::ostream& out, const LogEvent &le) {
   le.print(out);
   return out;
 }