minor readme correction

README.md

@@ -416,7 +416,7 @@ Please note that setting the exception bit for `failbit` is inappropriate for th
 
 #### Read from iterator range
 
-You can also parse JSON from an iterator range; that is, from any container accessible by iterators whose `value_type` is an integral type of 1, 2 or 4 bytes, for instance a `std::vector<std::uint8_t>`, or a `std::list<std::uint16_t>`:
+You can also parse JSON from an iterator range; that is, from any container accessible by iterators whose `value_type` is an integral type of 1, 2 or 4 bytes, which will be interpreted as UTF-8, UTF-16 and UTF-32 respectively. For instance, a `std::vector<std::uint8_t>`, or a `std::list<std::uint16_t>`:
 
 ```cpp
 std::vector<std::uint8_t> v = {'t', 'r', 'u', 'e'};
@@ -435,8 +435,6 @@ json j = json::parse(v);
 Since the parse function accepts arbitrary iterator ranges, you can provide your own data sources by implementing the `LegacyInputIterator` concept.
 
 ```cpp
-struct MyContainer;
-
 struct MyContainer {
   void advance();
   const char& get_current();
@@ -451,6 +449,7 @@ struct MyIterator {
 
     MyIterator& operator++() {
         MyContainer.advance();
+        return *this;
     }
 
     bool operator!=(const MyIterator& rhs) const {