From 15fbb49827597c9332fd7e62715de4e02070d0e2 Mon Sep 17 00:00:00 2001
From: Justin Riddell <arghnews@hotmail.co.uk>
Date: Wed, 28 Aug 2024 18:46:03 +0100
Subject: [PATCH] Fix gcc 8.1 - 8.3 bug and compilation
Fixes issue #4129
---
include/fmt/base.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/fmt/base.h b/include/fmt/base.h
index 671c2ec7ec5f..7bae9789491c 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -332,6 +332,7 @@ template <typename T>
using make_unsigned_t = typename std::make_unsigned<T>::type;
template <typename T>
using underlying_t = typename std::underlying_type<T>::type;
+template <typename T> using decay_t = typename std::decay<T>::type;
#if FMT_GCC_VERSION && FMT_GCC_VERSION < 500
// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
@@ -1580,7 +1581,8 @@ template <> struct is_output_iterator<appender, char> : std::true_type {};
template <typename It, typename T>
struct is_output_iterator<
- It, T, void_t<decltype(*std::declval<It&>()++ = std::declval<T>())>>
+ It, T,
+ void_t<decltype(*std::declval<decay_t<It>&>()++ = std::declval<T>())>>
: std::true_type {};
// A type-erased reference to an std::locale to avoid a heavy <locale> include.