Fix int->char conv warn

resolves #473

src/lib_json/json_reader.cpp

@@ -430,25 +430,25 @@ void Reader::readNumber() {
   char c = '0'; // stopgap for already consumed character
   // integral part
   while (c >= '0' && c <= '9')
-    c = (current_ = p) < end_ ? *p++ : 0;
+    c = (current_ = p) < end_ ? *p++ : '\0';
   // fractional part
   if (c == '.') {
-    c = (current_ = p) < end_ ? *p++ : 0;
+    c = (current_ = p) < end_ ? *p++ : '\0';
     while (c >= '0' && c <= '9')
-      c = (current_ = p) < end_ ? *p++ : 0;
+      c = (current_ = p) < end_ ? *p++ : '\0';
   }
   // exponential part
   if (c == 'e' || c == 'E') {
-    c = (current_ = p) < end_ ? *p++ : 0;
+    c = (current_ = p) < end_ ? *p++ : '\0';
     if (c == '+' || c == '-')
-      c = (current_ = p) < end_ ? *p++ : 0;
+      c = (current_ = p) < end_ ? *p++ : '\0';
     while (c >= '0' && c <= '9')
-      c = (current_ = p) < end_ ? *p++ : 0;
+      c = (current_ = p) < end_ ? *p++ : '\0';
   }
 }
 
 bool Reader::readString() {
-  Char c = 0;
+  Char c = '\0';
   while (current_ != end_) {
     c = getNextChar();
     if (c == '\\')
@@ -1394,20 +1394,20 @@ bool OurReader::readNumber(bool checkInf) {
   char c = '0'; // stopgap for already consumed character
   // integral part
   while (c >= '0' && c <= '9')
-    c = (current_ = p) < end_ ? *p++ : 0;
+    c = (current_ = p) < end_ ? *p++ : '\0';
   // fractional part
   if (c == '.') {
-    c = (current_ = p) < end_ ? *p++ : 0;
+    c = (current_ = p) < end_ ? *p++ : '\0';
     while (c >= '0' && c <= '9')
-      c = (current_ = p) < end_ ? *p++ : 0;
+      c = (current_ = p) < end_ ? *p++ : '\0';
   }
   // exponential part
   if (c == 'e' || c == 'E') {
-    c = (current_ = p) < end_ ? *p++ : 0;
+    c = (current_ = p) < end_ ? *p++ : '\0';
     if (c == '+' || c == '-')
-      c = (current_ = p) < end_ ? *p++ : 0;
+      c = (current_ = p) < end_ ? *p++ : '\0';
     while (c >= '0' && c <= '9')
-      c = (current_ = p) < end_ ? *p++ : 0;
+      c = (current_ = p) < end_ ? *p++ : '\0';
   }
   return true;
 }