Merge pull request #3891 from bog-dan-ro/master

More bit fields patches

include/flatbuffers/flatbuffers.h

@@ -1485,21 +1485,17 @@ volatile __attribute__((weak)) const char *flatbuffer_version_string =
 
 #endif  // !defined(_WIN32) && !defined(__CYGWIN__)
 
-#define DEFINE_BITMASK_OPERATORS(E)\
+#define DEFINE_BITMASK_OPERATORS(E, T)\
     inline E operator | (E lhs, E rhs){\
-        using T = std::underlying_type<E>::type;\
         return E(T(lhs) | T(rhs));\
     }\
     inline E operator & (E lhs, E rhs){\
-        using T = std::underlying_type<E>::type;\
         return E(T(lhs) & T(rhs));\
     }\
     inline E operator ^ (E lhs, E rhs){\
-        using T = std::underlying_type<E>::type;\
         return E(T(lhs) ^ T(rhs));\
     }\
     inline E operator ~ (E lhs){\
-        using T = std::underlying_type<E>::type;\
         return E(~T(lhs));\
     }\
     inline E operator |= (E &lhs, E rhs){\
@@ -1513,6 +1509,10 @@ volatile __attribute__((weak)) const char *flatbuffer_version_string =
     inline E operator ^= (E &lhs, E rhs){\
         lhs = lhs ^ rhs;\
         return lhs;\
+    }\
+    inline bool operator !(E rhs) \
+    {\
+        return !bool(T(rhs)); \
     }
 /// @endcond
 }  // namespace flatbuffers

src/idl_gen_cpp.cpp

@@ -166,6 +166,7 @@ static void GenEnum(const Parser &parser, EnumDef &enum_def,
   if (parser.opts.scoped_enums)
     code += " : " + GenTypeBasic(enum_def.underlying_type, false);
   code += " {\n";
+  int64_t anyv = 0;
   EnumVal *minv = nullptr, *maxv = nullptr;
   for (auto it = enum_def.vals.vec.begin();
        it != enum_def.vals.vec.end();
@@ -176,15 +177,25 @@ static void GenEnum(const Parser &parser, EnumDef &enum_def,
     code += NumToString(ev.value) + ",\n";
     minv = !minv || minv->value > ev.value ? &ev : minv;
     maxv = !maxv || maxv->value < ev.value ? &ev : maxv;
+    anyv |= ev.value;
   }
+  if (parser.opts.scoped_enums || parser.opts.prefixed_enums) {
     assert(minv && maxv);
+    if (enum_def.attributes.Lookup("bit_flags")) {
+      if (minv->value != 0) // If the user didn't defined NONE value
+        code += "  " + GenEnumVal(enum_def, "NONE", parser.opts) + " = 0,\n";
+      if (maxv->value != anyv) // If the user didn't defined ANY value
+        code += "  " + GenEnumVal(enum_def, "ANY", parser.opts) + " = " + NumToString(anyv) + "\n";
+    } else { // MIN & MAX are useless for bit_flags
       code += "  " + GenEnumVal(enum_def, "MIN", parser.opts) + " = ";
       code += GenEnumVal(enum_def, minv->name, parser.opts) + ",\n";
       code += "  " + GenEnumVal(enum_def, "MAX", parser.opts) + " = ";
       code += GenEnumVal(enum_def, maxv->name, parser.opts) + "\n";
+    }
+  }
   code += "};\n";
   if (parser.opts.scoped_enums && enum_def.attributes.Lookup("bit_flags"))
-    code += "DEFINE_BITMASK_OPERATORS(" + enum_def.name + ")\n";
+    code += "DEFINE_BITMASK_OPERATORS(" + enum_def.name + ", " +  GenTypeBasic(enum_def.underlying_type, false) + ")\n";
   code += "\n";
 
   // Generate a generate string table for enum values.