util/StringSplit: move code from StringView.hxx

src/util/StringSplit.hxx

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2013-2022 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.
+ */
+
+#pragma once
+
+#include <string_view>
+
+template<typename T>
+[[gnu::pure]]
+std::pair<std::basic_string_view<T>, std::basic_string_view<T>>
+PartitionWithout(const std::basic_string_view<T> haystack,
+		 const typename std::basic_string_view<T>::size_type separator) noexcept
+{
+	return {
+		haystack.substr(0, separator),
+		haystack.substr(separator + 1),
+	};
+}
+
+/**
+ * Split the string at the first occurrence of the given character.
+ * If the character is not found, then the first value is the whole
+ * string and the second value is nullptr.
+ */
+template<typename T>
+[[gnu::pure]]
+std::pair<std::basic_string_view<T>, std::basic_string_view<T>>
+Split(const std::basic_string_view<T> haystack, const T ch) noexcept
+{
+	const auto i = haystack.find(ch);
+	if (i == haystack.npos)
+		return {haystack, {}};
+
+	return PartitionWithout(haystack, i);
+}
+
+/**
+ * Split the string at the last occurrence of the given
+ * character.  If the character is not found, then the first
+ * value is the whole string and the second value is nullptr.
+ */
+template<typename T>
+[[gnu::pure]]
+std::pair<std::basic_string_view<T>, std::basic_string_view<T>>
+SplitLast(const std::basic_string_view<T> haystack, const T ch) noexcept
+{
+	const auto i = haystack.rfind(ch);
+	if (i == haystack.npos)
+		return {haystack, {}};
+
+	return PartitionWithout(haystack, i);
+}

src/util/StringView.hxx

@@ -32,6 +32,7 @@
 
 #include "ConstBuffer.hxx"
 #include "StringAPI.hxx"
+#include "StringSplit.hxx"
 
 #include <cstddef>
 #include <string_view>
@@ -114,11 +115,7 @@ struct BasicStringView : ConstBuffer<T> {
 	 */
 	[[gnu::pure]]
 	std::pair<BasicStringView<T>, BasicStringView<T>> Split(value_type ch) const noexcept {
-		const auto separator = Find(ch);
-		if (separator == nullptr)
-			return {*this, nullptr};
-
-		return {{begin(), separator}, {separator + 1, end()}};
+		return ::Split(static_cast<std::basic_string_view<T>>(*this), ch);
 	}
 
 	/**
@@ -128,11 +125,7 @@ struct BasicStringView : ConstBuffer<T> {
 	 */
 	[[gnu::pure]]
 	std::pair<BasicStringView<T>, BasicStringView<T>> SplitLast(value_type ch) const noexcept {
-		const auto separator = FindLast(ch);
-		if (separator == nullptr)
-			return {*this, nullptr};
-
-		return {{begin(), separator}, {separator + 1, end()}};
+		return ::SplitLast(static_cast<std::basic_string_view<T>>(*this), ch);
 	}
 
 	[[gnu::pure]]