intermediate changes

ref:d5f945ecdc1f5af1ad57e12787c6b8ed1a9f0f12

1 files changed, 30 insertions, 0 deletions

diff --git a/library/cpp/case_insensitive_string/case_insensitive_char_traits.h b/library/cpp/case_insensitive_string/case_insensitive_char_traits.h
new file mode 100644
index 0000000000..2717893c10
--- /dev/null
+++ b/library/cpp/case_insensitive_string/case_insensitive_char_traits.h
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <contrib/libs/libc_compat/string.h>
+
+#include <string>
+
+struct TCaseInsensitiveCharTraits : private std::char_traits<char> {
+    static bool eq(char c1, char c2) {
+        return to_upper(c1) == to_upper(c2);
+    }
+
+    static bool lt(char c1, char c2) {
+        return to_upper(c1) < to_upper(c2);
+    }
+
+    static int compare(const char* s1, const char* s2, std::size_t n);
+
+    static const char* find(const char* s, std::size_t n, char a);
+
+    using std::char_traits<char>::assign;
+    using std::char_traits<char>::char_type;
+    using std::char_traits<char>::copy;
+    using std::char_traits<char>::length;
+    using std::char_traits<char>::move;
+
+private:
+    static char to_upper(char ch) {
+        return std::toupper((unsigned char)ch);
+    }
+};