1 files changed, 138 insertions, 0 deletions
diff --git a/libcxx/test/support/constexpr_char_traits.h b/libcxx/test/support/constexpr_char_traits.h
new file mode 100644
index 00000000000..df43d8f7c19
--- /dev/null
+++ b/libcxx/test/support/constexpr_char_traits.h
@@ -0,0 +1,138 @@
+// -*- C++ -*-
+//===-------------------- constexpr_char_traits ---------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _CONSTEXPR_CHAR_TRAITS
+#define _CONSTEXPR_CHAR_TRAITS
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <class _CharT>
+struct constexpr_char_traits
+{
+    typedef _CharT    char_type;
+    typedef int       int_type;
+    typedef std::streamoff off_type;
+    typedef std::streampos pos_type;
+    typedef std::mbstate_t state_type;
+
+    static TEST_CONSTEXPR_CXX14 void assign(char_type& __c1, const char_type& __c2) TEST_NOEXCEPT
+        {__c1 = __c2;}
+
+    static TEST_CONSTEXPR bool eq(char_type __c1, char_type __c2) TEST_NOEXCEPT
+        {return __c1 == __c2;}
+
+    static TEST_CONSTEXPR  bool lt(char_type __c1, char_type __c2) TEST_NOEXCEPT
+        {return __c1 < __c2;}
+
+    static TEST_CONSTEXPR_CXX14 int              compare(const char_type* __s1, const char_type* __s2, size_t __n);
+    static TEST_CONSTEXPR_CXX14 size_t           length(const char_type* __s);
+    static TEST_CONSTEXPR_CXX14 const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
+    static TEST_CONSTEXPR_CXX14 char_type*       move(char_type* __s1, const char_type* __s2, size_t __n);
+    static TEST_CONSTEXPR_CXX14 char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n);
+    static TEST_CONSTEXPR_CXX14 char_type*       assign(char_type* __s, size_t __n, char_type __a);
+
+    static TEST_CONSTEXPR int_type  not_eof(int_type __c) TEST_NOEXCEPT
+        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
+
+    static TEST_CONSTEXPR char_type to_char_type(int_type __c) TEST_NOEXCEPT
+        {return char_type(__c);}
+
+    static TEST_CONSTEXPR int_type  to_int_type(char_type __c) TEST_NOEXCEPT
+        {return int_type(__c);}
+
+    static TEST_CONSTEXPR bool      eq_int_type(int_type __c1, int_type __c2) TEST_NOEXCEPT
+        {return __c1 == __c2;}
+
+    static TEST_CONSTEXPR int_type  eof() TEST_NOEXCEPT
+        {return int_type(EOF);}
+};
+
+
+template <class _CharT>
+TEST_CONSTEXPR_CXX14 int
+constexpr_char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
+{
+    for (; __n; --__n, ++__s1, ++__s2)
+    {
+        if (lt(*__s1, *__s2))
+            return -1;
+        if (lt(*__s2, *__s1))
+            return 1;
+    }
+    return 0;
+}
+
+template <class _CharT>
+TEST_CONSTEXPR_CXX14 size_t
+constexpr_char_traits<_CharT>::length(const char_type* __s)
+{
+    size_t __len = 0;
+    for (; !eq(*__s, char_type(0)); ++__s)
+        ++__len;
+    return __len;
+}
+
+template <class _CharT>
+TEST_CONSTEXPR_CXX14 const _CharT*
+constexpr_char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a)
+{
+    for (; __n; --__n)
+    {
+        if (eq(*__s, __a))
+            return __s;
+        ++__s;
+    }
+    return 0;
+}
+
+template <class _CharT>
+TEST_CONSTEXPR_CXX14 _CharT*
+constexpr_char_traits<_CharT>::move(char_type* __s1, const char_type* __s2, size_t __n)
+{
+    char_type* __r = __s1;
+    if (__s1 < __s2)
+    {
+        for (; __n; --__n, ++__s1, ++__s2)
+            assign(*__s1, *__s2);
+    }
+    else if (__s2 < __s1)
+    {
+        __s1 += __n;
+        __s2 += __n;
+        for (; __n; --__n)
+            assign(*--__s1, *--__s2);
+    }
+    return __r;
+}
+
+template <class _CharT>
+TEST_CONSTEXPR_CXX14 _CharT*
+constexpr_char_traits<_CharT>::copy(char_type* __s1, const char_type* __s2, size_t __n)
+{
+    assert(__s2 < __s1 || __s2 >= __s1+__n);
+    char_type* __r = __s1;
+    for (; __n; --__n, ++__s1, ++__s2)
+        assign(*__s1, *__s2);
+    return __r;
+}
+
+template <class _CharT>
+TEST_CONSTEXPR_CXX14 _CharT*
+constexpr_char_traits<_CharT>::assign(char_type* __s, size_t __n, char_type __a)
+{
+    char_type* __r = __s;
+    for (; __n; --__n, ++__s)
+        assign(*__s, __a);
+    return __r;
+}
+
+#endif // _CONSTEXPR_CHAR_TRAITS