1 files changed, 4 insertions, 5 deletions
diff --git a/src/sync.h b/src/sync.h
index 9274f50d8b..0871c5fb4d 100644
--- a/src/sync.h
+++ b/src/sync.h
@@ -9,7 +9,6 @@
 #include "threadsafety.h"
 
 #include <boost/thread/condition_variable.hpp>
-#include <boost/thread/locks.hpp>
 #include <boost/thread/mutex.hpp>
 #include <boost/thread/recursive_mutex.hpp>
 
@@ -197,7 +196,7 @@ private:
     int value;
 
 public:
-    CSemaphore(int init) : value(init) {}
+    explicit CSemaphore(int init) : value(init) {}
 
     void wait()
     {
@@ -266,9 +265,9 @@ public:
         fHaveGrant = false;
     }
 
-    CSemaphoreGrant() : sem(NULL), fHaveGrant(false) {}
+    CSemaphoreGrant() : sem(nullptr), fHaveGrant(false) {}
 
-    CSemaphoreGrant(CSemaphore& sema, bool fTry = false) : sem(&sema), fHaveGrant(false)
+    explicit CSemaphoreGrant(CSemaphore& sema, bool fTry = false) : sem(&sema), fHaveGrant(false)
     {
         if (fTry)
             TryAcquire();
@@ -281,7 +280,7 @@ public:
         Release();
     }
 
-    operator bool()
+    operator bool() const
     {
         return fHaveGrant;
     }