Introduce string utils

src/common/utils/string.hpp

@@ -0,0 +1,40 @@
+#pragma once
+#include <string>
+#include <ranges>
+#include <cwctype>
+#include <algorithm>
+
+namespace utils::string
+{
+	inline char char_to_lower(const char val)
+	{
+		return static_cast<char>(std::tolower(static_cast<unsigned char>(val)));
+	}
+
+	inline wchar_t char_to_lower(const wchar_t val)
+	{
+		return std::towlower(val);
+	}
+
+	template <class Elem, class Traits, class Alloc>
+	void to_lower_inplace(std::basic_string<Elem, Traits, Alloc>& str)
+	{
+		std::ranges::transform(str, str.begin(), [](const Elem e)
+		{
+			return char_to_lower(e);
+		});
+	}
+
+	template <class Elem, class Traits, class Alloc>
+	std::basic_string<Elem, Traits, Alloc> to_lower(std::basic_string<Elem, Traits, Alloc> str)
+	{
+		to_lower_inplace(str);
+		return str;
+	}
+
+	template <class Elem, class Traits, class Alloc>
+	std::basic_string<Elem, Traits, Alloc> to_lower_consume(std::basic_string<Elem, Traits, Alloc>& str)
+	{
+		return to_lower(std::move(str));
+	}
+}