Util/CharUtil: add wchar_t overloads

Needed for WStringView.

Makefile.am

@@ -419,6 +419,7 @@ libutil_a_SOURCES = \
 	src/util/ASCII.hxx \
 	src/util/UTF8.cxx src/util/UTF8.hxx \
 	src/util/CharUtil.hxx \
+	src/util/WCharUtil.hxx \
 	src/util/NumberParser.hxx \
 	src/util/MimeType.cxx src/util/MimeType.hxx \
 	src/util/StringBuffer.hxx \

src/lib/curl/Request.cxx

@@ -199,7 +199,8 @@ CurlRequest::HeaderFunction(StringView s)
 		return;
 
 	std::string name(header, value);
-	std::transform(name.begin(), name.end(), name.begin(), ToLowerASCII);
+	std::transform(name.begin(), name.end(), name.begin(),
+		       static_cast<char(*)(char)>(ToLowerASCII));
 
 	/* skip the colon */
 

src/util/CharUtil.hxx

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011-2014 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright (C) 2011-2017 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -30,6 +30,10 @@
 #ifndef CHAR_UTIL_HXX
 #define CHAR_UTIL_HXX
 
+#ifdef _UNICODE
+#include "WCharUtil.hxx"
+#endif
+
 constexpr
 static inline bool
 IsASCII(const unsigned char ch)

src/util/WCharUtil.hxx

@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2011-2017 Max Kellermann <max.kellermann@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef WCHAR_UTIL_HXX
+#define WCHAR_UTIL_HXX
+
+#include <wchar.h>
+
+constexpr
+static inline bool
+IsASCII(const wchar_t ch)
+{
+	return (ch & ~0x7f) == 0;
+}
+
+constexpr
+static inline bool
+IsWhitespaceOrNull(const wchar_t ch)
+{
+	return (unsigned)ch <= 0x20;
+}
+
+constexpr
+static inline bool
+IsWhitespaceNotNull(const wchar_t ch)
+{
+	return ch > 0 && ch <= 0x20;
+}
+
+/**
+ * Is the given character whitespace?  This calls the faster one of
+ * IsWhitespaceOrNull() or IsWhitespaceNotNull().  Use this if you
+ * want the fastest implementation, and you don't care if a null byte
+ * matches.
+ */
+constexpr
+static inline bool
+IsWhitespaceFast(const wchar_t ch)
+{
+	return IsWhitespaceOrNull(ch);
+}
+
+constexpr
+static inline bool
+IsPrintableASCII(wchar_t ch)
+{
+	return IsASCII(ch) && ch >= 0x20;
+}
+
+constexpr
+static inline bool
+IsDigitASCII(wchar_t ch)
+{
+	return ch >= '0' && ch <= '9';
+}
+
+constexpr
+static inline bool
+IsUpperAlphaASCII(wchar_t ch)
+{
+	return ch >= 'A' && ch <= 'Z';
+}
+
+constexpr
+static inline bool
+IsLowerAlphaASCII(wchar_t ch)
+{
+	return ch >= 'a' && ch <= 'z';
+}
+
+constexpr
+static inline bool
+IsAlphaASCII(wchar_t ch)
+{
+	return IsUpperAlphaASCII(ch) || IsLowerAlphaASCII(ch);
+}
+
+constexpr
+static inline bool
+IsAlphaNumericASCII(wchar_t ch)
+{
+	return IsAlphaASCII(ch) || IsDigitASCII(ch);
+}
+
+/**
+ * Convert the specified ASCII character (0x00..0x7f) to upper case.
+ * Unlike toupper(), it ignores the system locale.
+ */
+constexpr
+static inline wchar_t
+ToUpperASCII(wchar_t ch)
+{
+	return ch >= 'a' && ch <= 'z'
+		? (ch - ('a' - 'A'))
+		: ch;
+}
+
+/**
+ * Convert the specified ASCII character (0x00..0x7f) to lower case.
+ * Unlike tolower(), it ignores the system locale.
+ */
+constexpr
+static inline wchar_t
+ToLowerASCII(wchar_t ch)
+{
+	return ch >= 'A' && ch <= 'Z'
+		? (ch + ('a' - 'A'))
+		: ch;
+}
+
+#endif