Add a path formatter

include/fmt/std.h

@@ -0,0 +1,29 @@
+// Formatting library for C++ - formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_STD_H_
+#define FMT_STD_H_
+
+#include <version>
+
+#ifdef __cpp_lib_filesystem
+#  include <filesystem>
+
+namespace fmt {
+
+template <> struct formatter<std::filesystem::path> : formatter<string_view> {
+  template <typename FormatContext>
+  auto format(const path& p, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
+    return formatter<string_view>::format(p.string(), ctx);
+  }
+};
+
+}  // namespace fmt
+#endif
+
+#endif  // FMT_STD_H_

test/std-test.cc

@@ -0,0 +1,16 @@
+// Formatting library for C++ - tests of formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/std.h"
+
+#include "gtest/gtest.h"
+
+TEST(std_test, path) {
+#ifdef __cpp_lib_filesystem
+  EXPECT_EQ(fmt::format("{:8}", std::filesystem::path("foo")), "foo     ");
+#endif
+}