类内通过去const来实行修改内容
#includeclass A{public: A():m_width(0), m_height(0) { } void create() {
*(const_cast<int*> (&m_width)) = 10;
*(const_cast<int*> (&m_height)) = 100;
}public: const int m_width; const int m_height;};int main(){ A a; a.create(); printf("%d %d\n", a.m_width, a.m_height); a.m_width = 10;}