Firestore: Remove unnecessary brace initialization in call to AlphaNum (#12281)

Firestore/core/src/util/string_format.h

@@ -80,7 +80,7 @@ class FormatArg : public absl::AlphaNum {
   template <typename T,
             typename = typename std::enable_if<std::is_same<bool, T>{}>::type>
   FormatArg(T bool_value, internal::FormatChoice<0>)
-      : AlphaNum{bool_value ? "true" : "false"} {
+      : AlphaNum(bool_value ? "true" : "false") {
   }
 
 #if __OBJC__
@@ -91,7 +91,7 @@ class FormatArg : public absl::AlphaNum {
       typename T,
       typename = typename std::enable_if<objc::is_objc_pointer<T>{}>::type>
   FormatArg(T object, internal::FormatChoice<1>)
-      : AlphaNum{MakeStringView([object description])} {
+      : AlphaNum(MakeStringView([object description])) {
   }
 
   /**
@@ -99,7 +99,7 @@ class FormatArg : public absl::AlphaNum {
    * types are a special struct that aren't of a type derived from NSObject.
    */
   FormatArg(Class object, internal::FormatChoice<1>)
-      : AlphaNum{MakeStringView(NSStringFromClass(object))} {
+      : AlphaNum(MakeStringView(NSStringFromClass(object))) {
   }
 #endif
 
@@ -108,7 +108,7 @@ class FormatArg : public absl::AlphaNum {
    * handled specially to avoid ambiguity with generic pointers, which are
    * handled differently.
    */
-  FormatArg(std::nullptr_t, internal::FormatChoice<2>) : AlphaNum{"null"} {
+  FormatArg(std::nullptr_t, internal::FormatChoice<2>) : AlphaNum("null") {
   }
 
   /**
@@ -117,7 +117,7 @@ class FormatArg : public absl::AlphaNum {
    * handled differently.
    */
   FormatArg(const char* string_value, internal::FormatChoice<3>)
-      : AlphaNum{string_value == nullptr ? "null" : string_value} {
+      : AlphaNum(string_value == nullptr ? "null" : string_value) {
   }
 
   /**
@@ -126,7 +126,7 @@ class FormatArg : public absl::AlphaNum {
    */
   template <typename T>
   FormatArg(T* pointer_value, internal::FormatChoice<4>)
-      : AlphaNum{absl::Hex{reinterpret_cast<uintptr_t>(pointer_value)}} {
+      : AlphaNum(absl::Hex(reinterpret_cast<uintptr_t>(pointer_value))) {
   }
 
   /**
@@ -135,7 +135,7 @@ class FormatArg : public absl::AlphaNum {
    */
   template <typename T>
   FormatArg(T&& value, internal::FormatChoice<5>)
-      : AlphaNum{std::forward<T>(value)} {
+      : AlphaNum(std::forward<T>(value)) {
   }
 };