From 8d78045e7cb44d39ad4cd95dd27816b8749e1944 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <viz@fb.com>
Date: Mon, 18 May 2020 10:46:25 -0700
Subject: [PATCH] Move void_t to where it's used

---
 include/fmt/core.h   | 6 ------
 include/fmt/format.h | 7 +++++++
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index e5d94c5e..f1561f8c 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -278,9 +278,6 @@ namespace detail {
 // warnings.
 template <typename T> constexpr T const_check(T value) { return value; }
 
-// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
-template <typename... Ts> struct void_t_impl { using type = void; };
-
 FMT_NORETURN FMT_API void assert_fail(const char* file, int line,
                                       const char* message);
 
@@ -342,9 +339,6 @@ enum char8_type : unsigned char {};
 
 namespace internal = detail;  // DEPRECATED
 
-template <typename... Ts>
-using void_t = typename detail::void_t_impl<Ts...>::type;
-
 /**
   An implementation of ``std::basic_string_view`` for pre-C++17. It provides a
   subset of the API. ``fmt::basic_string_view`` is used for format strings even
diff --git a/include/fmt/format.h b/include/fmt/format.h
index a81c155b..257420bd 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -288,6 +288,13 @@ template <> constexpr int num_bits<fallback_uintptr>() {
                           std::numeric_limits<unsigned char>::digits);
 }
 
+
+// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
+template <typename... Ts> struct void_t_impl { using type = void; };
+
+template <typename... Ts>
+using void_t = typename detail::void_t_impl<Ts...>::type;
+
 // An approximation of iterator_t for pre-C++20 systems.
 template <typename T>
 using iterator_t = decltype(std::begin(std::declval<T&>()));