From 08ef0d0842b401ef928ff456df161d8bfacb0133 Mon Sep 17 00:00:00 2001
From: timsong-cpp <rs2740@gmail.com>
Date: Sat, 20 May 2023 03:32:21 -1000
Subject: [PATCH] fix formatter<char*> (#3432)

---
 include/fmt/core.h  |  2 +-
 test/format-test.cc | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index 8848939f..6e658021 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -2694,7 +2694,7 @@ struct formatter<T, Char,
   template <typename Char>                                               \
   struct formatter<Type, Char> : formatter<Base, Char> {                 \
     template <typename FormatContext>                                    \
-    auto format(const Type& val, FormatContext& ctx) const               \
+    auto format(Type const& val, FormatContext& ctx) const               \
         -> decltype(ctx.out()) {                                         \
       return formatter<Base, Char>::format(static_cast<Base>(val), ctx); \
     }                                                                    \
diff --git a/test/format-test.cc b/test/format-test.cc
index 6150e433..638bd143 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -2245,3 +2245,19 @@ TEST(format_test, format_named_arg_with_locale) {
 }
 
 #endif  // FMT_STATIC_THOUSANDS_SEPARATOR
+
+struct convertible_to_nonconst_cstring {
+    operator char*() const {
+        static char c[]="bar";
+        return c;
+    }
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<convertible_to_nonconst_cstring> : formatter<char*> {
+};
+FMT_END_NAMESPACE
+
+TEST(format_test, formatter_nonconst_char) {
+  EXPECT_EQ(fmt::format("{}", convertible_to_nonconst_cstring()), "bar");
+}