Create a generic type for types with an error list

boot/driver.cc

@@ -42,20 +42,10 @@ namespace boot
     }
 
     driver::driver(const char *input_file)
-        : input_file(input_file)
+        : error_container(input_file)
     {
     }
 
-    void driver::error(const yy::location& loc, const std::string& message)
-    {
-        m_errors.emplace_back(new boot::syntax_error(message, input_file, loc));
-    }
-
-    const std::list<std::unique_ptr<struct error>>& driver::errors() const noexcept
-    {
-        return m_errors;
-    }
-
     char escape_char(char escape)
     {
         switch (escape)