';'之前的预期类型说明符 代币

Question

I get the error "Expected type-specifier before ';' token" in a line of code marked below. Is it asking to specify the type of (*this)? Why wouldn't the compiler know the type of (*this)?

struct P{
};

struct R : public P{
  virtual P* copy(){
    return new(R(*this));  //error here
  }
};

Answer 1

You need to say: return new R(*this); That's the form of the non-placement new -expression. No extra parentheses.