関連ワード:  unary operator overloading using friend function in c++ program    unary operator overloading using friend function    unary operator overloading using friend function in c++    explain unary operator overloading with friend function in c++    unary minus operator overloading in c++ using friend function    when overloading unary operators using friend function it requires argument s    operator overloading using friend function  
結果 : unary operator overloading using friend function