diff --git a/include/crap/locale b/include/crap/locale
index 096b89f..9c356de 100644
--- a/include/crap/locale
+++ b/include/crap/locale
@@ -1,6 +1,8 @@
 #ifndef CRAP_LOCALE
 #define CRAP_LOCALE
 
+#include "locale.d/ctype.h"
+#include "locale.d/ctypebase.h"
 #include "locale.d/hasfacet.h"
 #include "locale.d/isalnumvalue.h"
 #include "locale.d/isalphavalue.h"
diff --git a/include/crap/locale.d/ctype.h b/include/crap/locale.d/ctype.h
new file mode 100644
index 0000000..b1534d5
--- /dev/null
+++ b/include/crap/locale.d/ctype.h
@@ -0,0 +1,84 @@
+#ifndef CRAP_LOCALE_CTYPE
+#define CRAP_LOCALE_CTYPE
+
+#include <locale>
+#include <type_traits>
+
+#include "ctypebase.h"
+#include "../algorithm.d/findvalue.h"
+#include "../functional.d/comparatorsfortype.h"
+#include "../string.d/string.h"
+#include "../version.d/libintegralconstantcallable.h"
+
+namespace crap
+{
+ template <class> struct ctype;
+
+ template <> struct ctype <char>
+ { //Defaults for C standard.
+  using char_type = char;
+  template <char_type ... Chars> using string_type =  string<char_type, Chars...>;
+  template <class> struct is;
+  template <char Char>
+	  struct is<std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> >;
+  template <char Char>
+	  struct is<std :: pair<ctypeBase :: digit>, std :: integral_constant<char, Char> >;
+ };
+
+ template <> struct ctype <wchar_t>
+ { //Requires execution encoding.
+ };
+
+ template <char Char> struct  :: ;
+ struct ctype <char> ::
+	is<std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> >
+ { //Assume ASCII, UTF-8 single octet or pure basic character set.
+  private:
+  //If certain of ASCII, ASCII superset or any encoding where digits are ordered, use binary search.
+  using result = findValue<char, Char, comparatorsForType <char> :: template
+	 EqualTo, '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'>;
+  public:
+  constexpr const static bool value = (result :: value != result :: npos);
+  using value_type = decltype(value);
+  constexpr operator value_type () const noexcept;
+#if (crap_lib_integral_constant_callable >= 201304L)
+  constexpr value_type operator () () const noexcept;
+#endif
+ };
+
+ template <char Char> struct  :: ;
+ struct ctype <char> ::
+	is<std :: pair<ctypeBase :: digit, std :: integral_constant<char, Char> > >
+ : ctype <char> ::
+	is<std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> >
+ {
+ };
+}
+
+template <char Char>
+inline constexpr crap :: ctype <char> ::
+        is <std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> > ::
+operator typename crap :: ctype <char> ::
+        is <std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> > ::
+value_type () const noexcept
+{
+ return crap :: ctype <char> ::
+	 is <std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> > ::
+	 value;
+}
+#if (crap_lib_integral_constant_callable >= 201304L)
+
+template <char Char>
+inline constexpr crap :: ctype <char> ::
+        is <std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> > ::
+value_type crap :: ctype <char> ::
+        is <std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> > ::
+operator () () const noexcept
+{
+ return crap :: ctype <char> ::
+	 is <std :: pair<std :: integral_constant<char, Char>, ctypeBase :: digit> > ::
+	 value;
+}
+#endif
+#endif
+