Question about friend in C++ - 未名空间MITBBS历史存档

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Question about friend in C++

Question about friend in C++# Programming - 葵花宝典

l*e2007-05-27 07:05

1 楼

to define A:Func1 as a friend function of class B, can we seperate the
declaration of A and B in different files?
I know the following codes work, but it uses forward declaration and
mandates the declaration of A and B exist in the same source file. Is there
any way to seperate the declaration of A and B into two header files?

l*e2007-05-27 07:05

2 楼

ding yi xia , you ren zhidao da an me?

there

【在 l******e 的大作中提到】

: to define A:Func1 as a friend function of class B, can we seperate the
: declaration of A and B in different files?
: I know the following codes work, but it uses forward declaration and
: mandates the declaration of A and B exist in the same source file. Is there
: any way to seperate the declaration of A and B into two header files?

p*o2007-05-27 07:05

3 楼

of course, but you still need to include the header of B in the header of A.
does it buy you anything?

there

【在 l******e 的大作中提到】

l*e2007-05-27 07:05

4 楼

header of B has A::Func1( ..) as the friend function, so when B is compiled,
the compiler cannot recognized A if they're in two files, I got compiler
error.

A.

【在 p****o 的大作中提到】

: of course, but you still need to include the header of B in the header of A.
: does it buy you anything?
:
: there

d*e2007-05-27 07:05

5 楼

try adding keyword 'class' before A. as such:
friend int class A::Func1(..)

compiled,

【在 l******e 的大作中提到】

: header of B has A::Func1( ..) as the friend function, so when B is compiled,
: the compiler cannot recognized A if they're in two files, I got compiler
: error.
:
: A.