locale independent util::parse_double

src/coders/commons.h

@@ -41,6 +41,19 @@ inline bool is_identifier_part(int c) {
     return is_identifier_start(c) || is_digit(c);
 }
 
+inline int hexchar2int(int c) {
+    if (c >= '0' && c <= '9') {
+        return c - '0';
+    }
+    if (c >= 'a' && c <= 'f') {
+        return 10 + c - 'a';
+    }
+    if (c >= 'A' && c <= 'F') {
+        return 10 + c - 'A';
+    }
+    return -1;
+}
+
 extern std::string escape_string(std::string s);
 
 class parsing_error : public std::runtime_error {