From 503dff93eccaa5fcb579a0eb1390cf5d9c307da4 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <viz@meta.com>
Date: Mon, 16 Sep 2024 20:15:54 -0700
Subject: [PATCH] Simplify has_formatter

---
 include/fmt/base.h | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/include/fmt/base.h b/include/fmt/base.h
index 16dc37ad..0456e334 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -1107,11 +1107,9 @@ struct use_formatter
                     !has_to_string_view<T>::value && !is_named_arg<T>::value &&
                     !use_format_as<T>::value> {};
 
-template <typename Char, typename T>
-auto has_formatter_impl(T* p)
-    -> decltype(formatter<remove_const_t<T>, Char>().format(
-                    *p, std::declval<buffered_context<Char>&>()),
-                std::true_type());
+template <typename Char, typename T, typename U = remove_const_t<T>>
+auto has_formatter_impl(T* p, buffered_context<Char>* ctx = nullptr)
+    -> decltype(formatter<U, Char>().format(*p, *ctx), std::true_type());
 template <typename Char> auto has_formatter_impl(...) -> std::false_type;
 // T can be const-qualified to check if it is const-formattable.
 template <typename T, typename Char> constexpr auto has_formatter() -> bool {