c++重载运算符两种形式的选择

Posted 2021-06-05 soak xiarl

 

可重载的操作符，摘录自c++ primer第四版 表14.1：

 

+	-	*	/	%	^
&	|	~	!	,	=
<	>	<=	>=	++	--
<<	>>	==	!=	&&	||
+=	-=	/=	%=	^=	&=
|=	*=	<<=	>>=	[]	()
->	->*	new	new []	delete	delete []

 

c++中可以重载运算符，有两种实现形式，成员函数和非成员函数。

如何选择，之前记得有本书里直接有个推荐形式的表，没找到。先把《exceptional c++》第20条中写的文字摘录下来：

 The standard requires that operators = () [] and -> must be members, and class-specific operators new, new[], delete, and delete[] must be static members.

For all other functions:

if the function is operator>> or operator<< for stream I/O,

or if it needs type conversions on its leftmost argument,

or if it can be implemented using the class\'s public interface alone,

make it a nonmember (and friend if needed in the first two cases)

if it needs to behave virtually, 

　　add a virtual member function to provide the virtual behavior,  and implement it in terms of that 

else

make it a member

看了这个描述，感觉还是要把那个表找到啊。。。