From 1980ca8c4e40d5323e3ac05ebc53457283ef4895 Mon Sep 17 00:00:00 2001
From: Yin Zhong <summivox@gmail.com>
Date: Sat, 30 Jan 2021 08:44:49 -0800
Subject: [PATCH] fix #2118: FMT_COMPILE did not work with tm formatter (#2119)

Co-authored-by: summivox <summivox@github.com>
---
 include/fmt/chrono.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/fmt/chrono.h b/include/fmt/chrono.h
index d68e8148..4b9aeeb1 100644
--- a/include/fmt/chrono.h
+++ b/include/fmt/chrono.h
@@ -423,7 +423,8 @@ template <typename Char> struct formatter<std::tm, Char> {
   }
 
   template <typename FormatContext>
-  auto format(const std::tm& tm, FormatContext& ctx) -> decltype(ctx.out()) {
+  auto format(const std::tm& tm, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
     basic_memory_buffer<Char> tm_format;
     tm_format.append(specs.begin(), specs.end());
     tm_format.push_back('\0');