initial skeleton for path module to replace std::filesystem

ostd/path.hh

@@ -0,0 +1,108 @@
+/** @addtogroup Utilities
+ * @{
+ */
+
+/** @file path.hh
+ *
+ * @brief A module for manipulation of filesystem paths.
+ *
+ * The path module implements facilities for manipulation of both pure
+ * paths and actual filesystem paths. POSIX and Windows path encodings
+ * are supported and common filesystem related operations are implemented
+ * in a portable manner.
+ *
+ * This module replaces the C++17 filesystem module, aiming to be simpler
+ * and higher level. For instance, it uses purely 8-bit encoding on all
+ * platforms, taking care of conversions internally.
+ *
+ * @copyright See COPYING.md in the project tree for further information.
+ */
+
+#ifndef OSTD_PATH_HH
+#define OSTD_PATH_HH
+
+#include <utility>
+#include <initializer_list>
+#include <type_traits>
+
+#include <ostd/string.hh>
+
+namespace ostd {
+
+/** @addtogroup Utilities
+ * @{
+ */
+
+struct path {
+    static constexpr char separator = '/';
+
+    enum class format {
+        native = 0,
+        posix,
+        windows
+    };
+
+    template<typename R>
+    path(R range, format fmt = format::native): p_fmt(fmt) {
+        if constexpr(std::is_constructible_v<std::string, R const &>) {
+            p_path = range;
+        } else if (range.empty()) {
+            p_path = ".";
+        } else {
+            p_path = range.front();
+            range.pop_front();
+            for (auto const &elem: range) {
+                append(elem);
+            }
+        }
+    }
+
+    path(format fmt = format::native): path(".", fmt) {}
+
+    template<typename T>
+    path(std::initializer_list<T> init, format fmt = format::native):
+        path(iter(init), fmt)
+    {}
+
+    path join(path const &p) const {
+        path ret{*this};
+        ret.append(p);
+        return ret;
+    }
+
+    path &append(path const &p) {
+        if (p_path != "/") {
+            p_path.push_back('/');
+        }
+        p_path += p.string();
+        return *this;
+    }
+
+    path &operator/=(path const &p) {
+        return append(p);
+    }
+
+    string_range string() const {
+        return p_path;
+    }
+
+    format path_format() const {
+        return p_fmt;
+    }
+
+private:
+    std::string p_path;
+    format p_fmt;
+};
+
+inline path operator/(path const &p1, path const &p2) {
+    return p1.join(p2);
+}
+
+/** @} */
+
+} /* namespace ostd */
+
+#endif
+
+/** @} */