diff --git a/include/fc/filesystem.hpp b/include/fc/filesystem.hpp
index bd091b5..d1a9c31 100644
--- a/include/fc/filesystem.hpp
+++ b/include/fc/filesystem.hpp
@@ -159,7 +159,7 @@ namespace fc {
   {
   public:
      inline ~temp_file_base() { remove(); }
-     inline operator bool() const { return _path; }
+     inline operator bool() const { return _path.valid(); }
      inline bool operator!() const { return !_path; }
      const fc::path& path() const;
      void remove();
diff --git a/include/fc/io/fstream.hpp b/include/fc/io/fstream.hpp
index fe05a9a..a11f915 100644
--- a/include/fc/io/fstream.hpp
+++ b/include/fc/io/fstream.hpp
@@ -29,7 +29,7 @@ namespace fc {
       enum seekdir { beg, cur, end };
 
       ifstream();
-      ifstream( const fc::path& file, int m );
+      ifstream( const fc::path& file, int m = binary);
       ~ifstream();
 
       void      open( const fc::path& file, int m );
diff --git a/include/fc/optional.hpp b/include/fc/optional.hpp
index 594bf18..a4e774d 100644
--- a/include/fc/optional.hpp
+++ b/include/fc/optional.hpp
@@ -183,7 +183,10 @@ namespace fc {
 
       bool valid()const     { return _valid;  }
       bool operator!()const { return !_valid; }
-      operator bool()const  { return _valid;  }
+
+      // this operation is not safe and can result in unintential 
+      // casts and comparisons, use valid() or !! 
+      explicit operator bool()const  { return _valid;  }
 
       T&       operator*()      { assert(_valid); return ref(); }
       const T& operator*()const { assert(_valid); return ref(); }
diff --git a/include/fc/variant.hpp b/include/fc/variant.hpp
index 7d2690f..4bed054 100644
--- a/include/fc/variant.hpp
+++ b/include/fc/variant.hpp
@@ -238,7 +238,7 @@ namespace fc
         variant( const optional<T>& v )
         {
            memset( this, 0, sizeof(*this) );
-           if( v ) *this = variant(*v);
+           if( v.valid() ) *this = variant(*v);
         }
 
         template<typename T>
diff --git a/src/filesystem.cpp b/src/filesystem.cpp
index a95aae7..7b4b8ec 100644
--- a/src/filesystem.cpp
+++ b/src/filesystem.cpp
@@ -356,7 +356,7 @@ namespace fc {
 
    void temp_file_base::remove()
    {
-      if (_path)
+      if (_path.valid())
       {
          try
          {
diff --git a/src/log/logger_config.cpp b/src/log/logger_config.cpp
index 22465de..413be71 100644
--- a/src/log/logger_config.cpp
+++ b/src/log/logger_config.cpp
@@ -36,11 +36,11 @@ namespace fc {
          auto lgr = logger::get( cfg.loggers[i].name );
 
          // TODO: finish configure logger here...
-         if( cfg.loggers[i].parent ) {
+         if( cfg.loggers[i].parent.valid() ) {
             lgr.set_parent( logger::get( *cfg.loggers[i].parent ) );
          }
          lgr.set_name(cfg.loggers[i].name);
-         if( cfg.loggers[i].level ) lgr.set_log_level( *cfg.loggers[i].level );
+         if( cfg.loggers[i].level.valid() ) lgr.set_log_level( *cfg.loggers[i].level );
          
 
          for( auto a = cfg.loggers[i].appenders.begin(); a != cfg.loggers[i].appenders.end(); ++a ){
diff --git a/src/network/url.cpp b/src/network/url.cpp
index 23a7e79..3456b3c 100644
--- a/src/network/url.cpp
+++ b/src/network/url.cpp
@@ -59,7 +59,7 @@ namespace fc
            _path = fc::path( "/" ) / _lpath;
 #endif
            fc::getline( ss, _largs );
-           if( _args && _args->size() ) 
+           if( _args.valid() && _args->size() ) 
            {
              // TODO: args = fc::move(_args);
            }
@@ -88,16 +88,16 @@ namespace fc
   {
       fc::stringstream ss;
       ss<<my->_proto<<"://";
-      if( my->_user ) {
+      if( my->_user.valid() ) {
         ss << *my->_user;
-        if( my->_pass ) {
+        if( my->_pass.valid() ) {
           ss<<":"<<*my->_pass;
         }
         ss<<"@";
       }
-      if( my->_host ) ss<<*my->_host;
-      if( my->_port ) ss<<":"<<*my->_port;
-      if( my->_path ) ss<<my->_path->generic_string();
+      if( my->_host.valid() ) ss<<*my->_host;
+      if( my->_port.valid() ) ss<<":"<<*my->_port;
+      if( my->_path.valid() ) ss<<my->_path->generic_string();
     //  if( my->_args ) ss<<"?"<<*my->_args;
       return ss.str();
   }