From 51d05521e96870daef27cef95840fbb5ea287370 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <viz@fb.com>
Date: Thu, 30 Jul 2020 09:42:24 -0700
Subject: [PATCH] Workaround broken numeric_limites, part 2 (#1787)

---
 include/fmt/format.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/fmt/format.h b/include/fmt/format.h
index 8e93a565..abf2ed9a 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -731,13 +731,18 @@ class FMT_API format_error : public std::runtime_error {
 
 namespace detail {
 
+template <typename T>
+constexpr bool is_signed() {
+  return std::numeric_limits<T>::is_signed || std::is_same<T, int128_t>();
+}
+
 // Returns true if value is negative, false otherwise.
 // Same as `value < 0` but doesn't produce warnings if T is an unsigned type.
-template <typename T, FMT_ENABLE_IF(std::numeric_limits<T>::is_signed)>
+template <typename T, FMT_ENABLE_IF(is_signed<T>())>
 FMT_CONSTEXPR bool is_negative(T value) {
   return value < 0;
 }
-template <typename T, FMT_ENABLE_IF(!std::numeric_limits<T>::is_signed)>
+template <typename T, FMT_ENABLE_IF(!is_signed<T>())>
 FMT_CONSTEXPR bool is_negative(T) {
   return false;
 }