rules-cpp

C-style casts are dangerous in C++ — they silently perform reinterpret_cast when no other cast works. Use explicit C++ casts: static_cast, dynamic_cast, const_cast.

gets() has no bounds checking and causes buffer overflows — removed from C11 and deprecated in C++11. Use std::getline(std::cin, str) or fgets() instead.

memcpy() with sizeof() — verify the size argument is the destination buffer size, not the source pointer size (a common mistake with pointer-decay). Prefer std::copy(), std::memcpy with explicit checked sizes, or std::span (C++20) to make the bounds explicit.

printf()/fprintf() called with a non-literal format string (CWE-134: Format String Vulnerability). A user-controlled format string can read arbitrary stack memory (%x/%s) or write to arbitrary addresses (%n). Always pass a string literal as the format: printf("%s", variable) not printf(variable).

Raw new/delete is error-prone — use-after-free, double-free, and leaks are common. Prefer std::make_unique<T>() or std::make_shared<T>() to enforce RAII ownership.

reinterpret_cast bypasses type safety and can produce undefined behavior if the types are incompatible. Use static_cast where possible, or redesign to avoid the cast.

scanf("%s", ...) reads input with no length limit, causing a stack buffer overflow when input exceeds the destination buffer size (CWE-121). Use scanf("%Ns", ...) where N is buffer size minus 1, or prefer std::cin with std::string / fgets().

sprintf() does not check buffer bounds. Use snprintf() with an explicit limit, or preferably std::to_string(), std::format() (C++20), or ostringstream.

strcpy() and strcat() cause buffer overflows. Use std::string for string operations in C++, or strlcpy/strlcat if you must use C strings.

std::system() with user-controlled input enables command injection. Use POSIX exec*() functions with an argv array, or a cross-platform subprocess library.

Uncaught exceptions call std::terminate(). Ensure throwing code is wrapped in try/catch at appropriate boundaries, or mark functions noexcept if they should not throw.