From 04e3a79f762aa28bb43a5d58e95ed168389f0c7e Mon Sep 17 00:00:00 2001
From: Victor Zverovich <viz@fb.com>
Date: Sun, 12 Sep 2021 12:23:45 -0700
Subject: [PATCH] Use memcpy in more cases in copy2

---
 include/fmt/format.h | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/include/fmt/format.h b/include/fmt/format.h
index 2621cf84..c94fbece 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1050,17 +1050,13 @@ inline auto equal2(const char* lhs, const char* rhs) -> bool {
 
 // Copies two characters from src to dst.
 template <typename Char>
-FMT_CONSTEXPR20 FMT_INLINE void copy2(Char* dst, const char* src) { 
-  if (!is_constant_evaluated() && std::is_same<Char, char>::value) {
-    memcpy(dst, src, 2); 
-  } else {
-    // We read both bytes before writing so that the compiler can do it in
-    // one pair of read/write instructions (even if Char aliases char)
-    char dc0 = *src++;
-    char dc1 = *src;
-    *dst++ = static_cast<Char>(dc0);
-    *dst = static_cast<Char>(dc1);
+FMT_CONSTEXPR20 FMT_INLINE void copy2(Char* dst, const char* src) {
+  if (!is_constant_evaluated() && sizeof(Char) == sizeof(char)) {
+    memcpy(dst, src, 2);
+    return;
   }
+  *dst++ = static_cast<Char>(*src++);
+  *dst = static_cast<Char>(*src);
 }
 
 template <typename Iterator> struct format_decimal_result {