From 796662a612023090a421f9a397fe58b506e4829d Mon Sep 17 00:00:00 2001
From: Victor Zverovich <viz@fb.com>
Date: Mon, 27 Dec 2021 09:38:06 -0800
Subject: [PATCH] Escape range items convertible to std::string_view

---
 include/fmt/ranges.h | 11 ++++++++++-
 test/ranges-test.cc  | 11 +++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/include/fmt/ranges.h b/include/fmt/ranges.h
index 71474f32..ff9054d4 100644
--- a/include/fmt/ranges.h
+++ b/include/fmt/ranges.h
@@ -65,7 +65,9 @@ template <typename T> class is_std_string_like {
 
  public:
   static FMT_CONSTEXPR_DECL const bool value =
-      is_string<T>::value || !std::is_void<decltype(check<T>(nullptr))>::value;
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 template <typename Char>
@@ -520,6 +522,13 @@ auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
   return out;
 }
 
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
 template <typename Char, typename OutputIt, typename Arg,
           FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
 OutputIt write_range_entry(OutputIt out, const Arg v) {
diff --git a/test/ranges-test.cc b/test/ranges-test.cc
index 86dd5520..63cb8c8b 100644
--- a/test/ranges-test.cc
+++ b/test/ranges-test.cc
@@ -350,3 +350,14 @@ TEST(ranges_test, escape_string) {
               "[\"\\xf4\\x8f\\xbf\\xc0\"]");
   }
 }
+
+#ifdef FMT_USE_STRING_VIEW
+struct convertible_to_string_view {
+  operator std::string_view() const { return "foo"; }
+};
+
+TEST(ranges_test, escape_convertible_to_string_view) {
+  EXPECT_EQ(fmt::format("{}", std::vector<convertible_to_string_view>(1)),
+            "[\"foo\"]");
+}
+#endif  // FMT_USE_STRING_VIEW