[ 2009-10-28 Ganesh provides two possible resolutions and expresses a preference for the second: ]

1. Replace [char.traits.specializations.char16_t] para 3 with:

   The member eof() shall return an implementation-defined constant that cannot appear as a valid UTF-16 code unit UINT_LEAST16_MAX [Note: this value is guaranteed to be a permanently reserved UCS-2 code position if UINT_LEAST16_MAX == 0xFFFF and it's not a UCS-2 code position otherwise — end note].

   Replace [char.traits.specializations.char32_t] para 3 with:

   The member eof() shall return an implementation-defined constant that cannot appear as a Unicode code point UINT_LEAST32_MAX [Note: this value is guaranteed to be a permanently reserved UCS-4 code position if UINT_LEAST32_MAX == 0xFFFFFFFF and it's not a UCS-4 code position otherwise — end note].

2. In [char.traits.specializations.char16_t], in the definition of char_traits<char16_t> replace the definition of nested typedef int_type with:

   namespace std {
     template<> struct char_traits<char16_t> {
       typedef char16_t         char_type;
       typedef uint_least16_t uint_fast16_t int_type;
        ...
   

   Replace [char.traits.specializations.char16_t] para 3 with:

   The member eof() shall return an implementation-defined constant that cannot appear as a valid UTF-16 code unit UINT_FAST16_MAX [Note: this value is guaranteed to be a permanently reserved UCS-2 code position if UINT_FAST16_MAX == 0xFFFF and it's not a UCS-2 code position otherwise — end note].

   In [char.traits.specializations.char32_t], in the definition of char_traits<char32_t> replace the definition of nested typedef int_type with:

   namespace std {
     template<> struct char_traits<char32_t> {
       typedef char32_t         char_type;
       typedef uint_least32_t uint_fast32_t int_type;
        ...
   

   Replace [char.traits.specializations.char32_t] para 3 with:

   The member eof() shall return an implementation-defined constant that cannot appear as a Unicode code point UINT_FAST32_MAX [Note: this value is guaranteed to be a permanently reserved UCS-4 code position if UINT_FAST32_MAX == 0xFFFFFFFF and it's not a UCS-4 code position otherwise — end note].