fixed an issue with non portability

README.md

@@ -262,6 +262,7 @@ I deeply appreciate the help of the following people.
 - [elliotgoodrich](https://github.com/elliotgoodrich) fixed an issue with double deletion in the iterator classes.
 - [kirkshoop](https://github.com/kirkshoop) made the iterators of the class composable to other libraries.
 - [wancw](https://github.com/wanwc) fixed a bug that hindered the class to compile with Clang.
+- Tomas Åblad found a bug in the iterator implementation.
 
 Thanks a lot for helping out!
 

test/json_unit.cc

@@ -2065,8 +2065,8 @@ TEST_CASE("Parser")
         CHECK(json::parse("10000.0E-4") == json(1));
 
         // 64 bit integers
-        CHECK(json::parse("9223372036854775807") == json(9223372036854775807));
-        CHECK(json::parse("-9223372036854775807") == json(-9223372036854775807));
+        CHECK(json::parse("9000000000000000000") == json(9000000000000000000));
+        CHECK(json::parse("-9000000000000000000") == json(-9000000000000000000));
 
         // trailing zero is not allowed
         //CHECK_THROWS_AS(json::parse("01"), std::invalid_argument);