Method calloc

sql/sql_class.h:1362–1368

  template <typename T=char>
  inline T* calloc(size_t size) const
  {
    void* ptr= alloc_root(mem_root, sizeof(T)*size);
    if (ptr)
      bzero(ptr, sizeof(T)*size);
    return (T*)ptr;
  }
  inline char *strdup(const char *str) const
  { return strdup_root(mem_root,str); }
  inline char *strmake(const char *str, size_t size) const