Revert "fix "no viable conversion from ... to 'bool'""

This reverts commit df9ae3ab9b37fde803f26c6bc4eaadfd67fc1d07.

4 files changed, 4 insertions, 4 deletions

diff --git a/src/account.h b/src/account.h
index 4a4041b7..d1377c39 100644
--- a/src/account.h
+++ b/src/account.h
@@ -261,7 +261,7 @@ public:
   mutable optional<xdata_t> xdata_;
 
   bool has_xdata() const {
-    return xdata_ != NULL;
+    return xdata_;
   }
   void clear_xdata();
   xdata_t& xdata() {
diff --git a/src/item.h b/src/item.h
index d194ac07..beb32a04 100644
--- a/src/item.h
+++ b/src/item.h
@@ -191,7 +191,7 @@ public:
   static bool use_aux_date;
 
   virtual bool has_date() const {
-    return _date != NULL;
+    return _date;
   }
 
   virtual date_t date() const {
diff --git a/src/post.h b/src/post.h
index c4fc3827..c2f77b32 100644
--- a/src/post.h
+++ b/src/post.h
@@ -205,7 +205,7 @@ public:
   mutable optional<xdata_t> xdata_;
 
   bool has_xdata() const {
-    return xdata_ != NULL;
+    return xdata_;
   }
   void clear_xdata() {
     xdata_ = none;
diff --git a/src/times.h b/src/times.h
index d2f7bb19..2a5b9277 100644
--- a/src/times.h
+++ b/src/times.h
@@ -568,7 +568,7 @@ public:
   void   stabilize(const optional<date_t>& date = none);
 
   bool   is_valid() const {
-    return start != NULL;
+    return start;
   }
 
   /** Find the current or next period containing date.  Returns false if