Don't bother supporting a filename

2022/13.cpp

@@ -47,7 +47,7 @@ auto ParseTree(std::string::iterator & begin, std::string::iterator end) -> Tree
     switch (*begin++) {
       case ',': goto top;
       case ']': return Tree{std::move(subtrees)};
-      default: assert(false);
+      default: throw std::runtime_error{"bad tree list"};
     }
   } else if (isdigit(*begin)) {
     auto number_end = std::find_if_not(begin, end, isdigit);
@@ -56,7 +56,7 @@ auto ParseTree(std::string::iterator & begin, std::string::iterator end) -> Tree
     std::int64_t number = std::stoll(number_str);
     return Tree{number};
   } else {
-    assert(false);
+    throw std::runtime_error{"bad tree start"};
   }
 }