Move size_ initialization to initializer list (fmtlib#2529)

Author: phprus

include/fmt/core.h

@@ -433,13 +433,12 @@ template <typename Char> class basic_string_view {
    */
   FMT_CONSTEXPR_CHAR_TRAITS
   FMT_INLINE
-  basic_string_view(const Char* s) : data_(s) {
-    if (detail::const_check(std::is_same<Char, char>::value &&
-                            !detail::is_constant_evaluated(true)))
-      size_ = std::strlen(reinterpret_cast<const char*>(s));
-    else
-      size_ = std::char_traits<Char>::length(s);
-  }
+  basic_string_view(const Char* s)
+      : data_(s),
+        size_(detail::const_check(std::is_same<Char, char>::value &&
+                                  !detail::is_constant_evaluated(true))
+                  ? std::strlen(reinterpret_cast<const char*>(s))
+                  : std::char_traits<Char>::length(s)) {}
 
   /** Constructs a string reference from a ``std::basic_string`` object. */
   template <typename Traits, typename Alloc>

include/fmt/format.h

@@ -2118,8 +2118,7 @@ FMT_CONSTEXPR_CHAR_TRAITS auto write(OutputIt out, const Char* value)
   if (!value) {
     throw_format_error("string pointer is null");
   } else {
-    auto length = std::char_traits<Char>::length(value);
-    out = write(out, basic_string_view<Char>(value, length));
+    out = write(out, basic_string_view<Char>(value));
   }
   return out;
 }