maybe a simpler unique_ptr

2022/25.cpp

@@ -13,6 +13,8 @@
 
 namespace {
 
+using It = std::istream_iterator<std::string>;
+
 // 
 template <typename T>
 auto DivMod(T dividend, T divisor) -> std::pair<T, T>
@@ -59,8 +61,7 @@ auto ToInt(std::string const& str) -> T
 
 auto Solve(std::istream & in) -> std::string
 {
-  using It = std::istream_iterator<std::string>;
-  return FromInt(std::transform_reduce(It(in), It(), 0, std::plus(), ToInt<std::int64_t>));
+  return FromInt(std::transform_reduce(It{in}, It{}, std::int64_t{}, std::plus(), ToInt<std::int64_t>));
 }
 
 } // namespace