template<typename Char>
struct char_traits {
// types:
typedef typename std::char_traits<Char>::char_type char_type;
typedef typename std::char_traits<Char>::int_type int_type;
typedef typename std::char_traits<Char>::off_type off_type;
typedef typename std::char_traits<Char>::pos_type pos_type;
typedef typename std::char_traits<Char>::state_type state_type;
// character operations:
static void assign(char_type& c1, char_type const& c2) SPROUT_NOEXCEPT;
static SPROUT_CONSTEXPR bool eq(char_type c1, char_type c2) SPROUT_NOEXCEPT;
static SPROUT_CONSTEXPR bool lt(char_type c1, char_type c2) SPROUT_NOEXCEPT;
// string operations:
static SPROUT_CONSTEXPR int compare(char_type const* s1, char_type const* s2, std::size_t n);
static SPROUT_CONSTEXPR std::size_t length(char_type const* s);
static SPROUT_CONSTEXPR char_type const* find(char_type const* s, std::size_t n, char_type const& a);
static char_type* move(char_type* s1, char_type const* s2, std::size_t n);
static char_type* copy(char_type* s1, char_type const* s2, std::size_t n);
static char_type* assign(char_type* s, std::size_t n, char_type a);
// integer type operations:
static SPROUT_CONSTEXPR int_type not_eof(int_type c) SPROUT_NOEXCEPT;
static SPROUT_CONSTEXPR char_type to_char_type(int_type c) SPROUT_NOEXCEPT;
static SPROUT_CONSTEXPR int_type to_int_type(char_type c) SPROUT_NOEXCEPT;
static SPROUT_CONSTEXPR bool eq_int_type(int_type c1, int_type c2) SPROUT_NOEXCEPT;
static SPROUT_CONSTEXPR int_type eof() SPROUT_NOEXCEPT;
// string operations (for iterator):
template<typename ConstInputIterator>
static SPROUT_CONSTEXPR int compare(char_type const* s1, ConstInputIterator s2, std::size_t n);
template<typename ConstInputIterator>
static SPROUT_CONSTEXPR int compare(ConstInputIterator s1, char_type const* s2, std::size_t n);
template<typename ConstIterator1, typename ConstIterator2>
static SPROUT_CONSTEXPR int compare(ConstIterator1 s1, ConstIterator2 s2, std::size_t n);
template<typename ConstInputIterator>
static SPROUT_CONSTEXPR std::size_t length(ConstInputIterator s);
template<typename ConstInputIterator>
static SPROUT_CONSTEXPR ConstInputIterator find(ConstInputIterator s, std::size_t n, char_type const& a);
template<typename OutputIterator, typename ConstInputIterator>
static OutputIterator move(OutputIterator s1, ConstInputIterator s2, std::size_t n);
template<typename OutputIterator, typename ConstInputIterator>
static OutputIterator copy(OutputIterator s1, ConstInputIterator s2, std::size_t n);
template<typename OutputIterator>
static OutputIterator assign(OutputIterator s, std::size_t n, char_type a);
};