diff --git a/include/lol/base/string.h b/include/lol/base/string.h
new file mode 100644
index 00000000..ae472bab
--- /dev/null
+++ b/include/lol/base/string.h
@@ -0,0 +1,142 @@
+//
+//  Lol Engine
+//
+//  Copyright © 2010—2020 Sam Hocevar <sam@hocevar.net>
+//            © 2013—2015 Benjamin “Touky” Huet <huet.benjamin@gmail.com>
+//
+//  Lol Engine is free software. It comes without any warranty, to
+//  the extent permitted by applicable law. You can redistribute it
+//  and/or modify it under the terms of the Do What the Fuck You Want
+//  to Public License, Version 2, as published by the WTFPL Task Force.
+//  See http://www.wtfpl.net/ for more details.
+//
+
+#pragma once
+
+//
+// The string tools
+// ————————————————
+// Contains some utilities to work with std::string objects.
+//
+
+#include <vector>
+#include <string>
+#include <algorithm> // std::transform
+#include <cstdarg>   // va_list
+#include <cctype>    // size_t
+
+namespace lol
+{
+
+// Split a string along a single separator
+template<typename T>
+std::vector<std::basic_string<T>> split(std::basic_string<T> const &s,
+                                        T sep = T('\n'))
+{
+    std::vector<std::basic_string<T>> ret;
+    size_t start = 0, end = 0;
+    while ((end = s.find(sep, start)) != std::basic_string<T>::npos)
+    {
+        ret.push_back(s.substr(start, end - start));
+        start = end + 1;
+    }
+    ret.push_back(s.substr(start));
+    return ret;
+}
+
+// Split a string along multiple separator
+template<typename T>
+std::vector<std::basic_string<T>> split(std::basic_string<T> const &s,
+                                        std::basic_string<T> const &seps)
+{
+    std::vector<std::string> ret;
+    size_t start = s.find_first_not_of(seps), end = 0;
+
+    while ((end = s.find_first_of(seps, start)) != std::basic_string<T>::npos)
+    {
+        ret.push_back(s.substr(start, end - start));
+        start = s.find_first_not_of(seps, end);
+    }
+    if (start != std::string::npos)
+        ret.push_back(s.substr(start));
+
+    return ret;
+
+}
+
+// Check whether a string starts or ends with a given substring
+template<typename T>
+bool starts_with(std::basic_string<T> const &s,
+                 std::basic_string<T> const &prefix)
+{
+    return s.size() >= prefix.size() &&
+           s.compare(0, prefix.size(), prefix) == 0;
+}
+
+template<typename T>
+bool ends_with(std::basic_string<T> const &s,
+               std::basic_string<T> const &suffix)
+{
+    return s.size() >= suffix.size() &&
+           s.compare(s.size() - suffix.size(), suffix.size(), suffix) == 0;
+}
+
+// Convert a string to lowercase or uppercase
+template<typename T>
+std::basic_string<T> tolower(std::basic_string<T> const &s)
+{
+    std::string ret;
+    std::transform(s.begin(), s.end(), std::back_inserter(ret),
+                   [](T c){ return std::tolower(c); });
+    return ret;
+}
+
+template<typename T>
+std::basic_string<T> toupper(std::basic_string<T> const &s)
+{
+    std::string ret;
+    std::transform(s.begin(), s.end(), std::back_inserter(ret),
+                   [](T c){ return std::toupper(c); });
+    return ret;
+}
+
+// Format a string, printf-style
+template<typename T = char> LOL_ATTR_FORMAT(1, 2)
+std::basic_string<T> format(T const *format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    std::string ret = vformat(format, ap);
+    va_end(ap);
+    return ret;
+}
+
+template<typename T = char>
+std::basic_string<T> vformat(char const *format, va_list ap)
+{
+    va_list ap2;
+#if defined va_copy || !defined _MSC_VER
+    // Visual Studio 2010 does not support va_copy.
+    va_copy(ap2, ap);
+#else
+    ap2 = ap;
+#endif
+
+    // vsnprintf() tells us how many characters we need, not counting
+    // the terminating null character.
+    size_t needed = vsnprintf(nullptr, 0, format, ap2);
+
+#if defined va_copy || !defined _MSC_VER
+    // do not call va_end() if va_copy() wasn't called.
+    va_end(ap2);
+#endif
+
+    std::string ret;
+    ret.resize(needed);
+    vsnprintf(&ret[0], needed + 1, format, ap);
+
+    return ret;
+}
+
+} /* namespace lol */
+
diff --git a/legacy/lol/base/string.h b/legacy/lol/base/string.h
deleted file mode 100644
index d32efd0f..00000000
--- a/legacy/lol/base/string.h
+++ /dev/null
@@ -1,46 +0,0 @@
-//
-//  Lol Engine
-//
-//  Copyright © 2010—2018 Sam Hocevar <sam@hocevar.net>
-//            © 2013—2015 Benjamin “Touky” Huet <huet.benjamin@gmail.com>
-//
-//  Lol Engine is free software. It comes without any warranty, to
-//  the extent permitted by applicable law. You can redistribute it
-//  and/or modify it under the terms of the Do What the Fuck You Want
-//  to Public License, Version 2, as published by the WTFPL Task Force.
-//  See http://www.wtfpl.net/ for more details.
-//
-
-#pragma once
-
-//
-// The string tools
-// ----------------
-// Contains some utilities to work with std::string objects.
-//
-
-#include <string>
-
-namespace lol
-{
-
-/* Split a string along a single separator */
-array<std::string> split(std::string const &s, char sep = '\n');
-
-/* Split a string along multiple separators */
-array<std::string> split(std::string const &s, std::string const &seps);
-
-/* Check whether a string starts or ends with a given substring */
-bool starts_with(std::string const &s, std::string const &prefix);
-bool ends_with(std::string const &s, std::string const &suffix);
-
-/* Convert a string to lowercase or uppercase */
-std::string tolower(std::string const &s);
-std::string toupper(std::string const &s);
-
-/* Format a string, printf-style */
-std::string format(char const *format, ...) LOL_ATTR_FORMAT(1, 2);
-std::string vformat(char const *format, va_list ap);
-
-} /* namespace lol */
-