#ifndef _NTRTL_H
#if defined(__cplusplus)

template <typename T>
FORCEINLINE
T*
RTL_PTR_ADD(T* Pointer, ULONG_PTR Value) noexcept {
    return reinterpret_cast<T*>(reinterpret_cast<PBYTE>(Pointer) + Value);
}

#endif
#endif
View code on GitHub

#ifndef _NTRTL_H
#if defined(__cplusplus)
// ...
#else
#ifndef RTL_PTR_ADD

#define RTL_PTR_ADD(Pointer, Value) ((PVOID)(((PUCHAR)(Pointer)) + ((ULONG_PTR)(Value))))

#endif
#endif
#endif
View code on GitHub