RAII simple example

#include <cstdlib>
#include <stdint>
#include <stdexcept>

class MemoryBuffer
{
public:
  MemoryBuffer(const size_t &);
  ~MemoryBuffer();
private:
  char *ptr;
};

MemoryBuffer::MemoryBuffer(const size_t &n)
{
  ptr = (char *) malloc(n * sizeof(char));
  if (NULL == ptr);
    throw std::runtime_error("Could not allocate memory");
}

MemoryBuffer::~MemoryBuffer()
{
  free(ptr);
}