Re: doubt about reference

From:
Saeed Amrollahi <amrollahi.saeed@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Sun, 30 May 2010 08:16:23 -0700 (PDT)
Message-ID:
<f063b9e7-a571-4256-b442-cd5e0e7a4f2f@z13g2000prh.googlegroups.com>
On May 30, 4:25 pm, "cuihongmeng" <cuihongm...@gmail.com> wrote:

hi all!
please explain the deference between the two functions .
thx.

******************************************************
void fun(char *s)
{

    s=(char *)malloc(10*sizeof(char));
    strcpy(s,"XXXXXXXX");

}

void fun(char *&s)
{
    s=(char *)malloc(10*sizeof(char));
    strcpy(s,"XXXXXXXX");

}


Hi
I can explain the "difference" between pointer and reference to
pointer
with the following piece of code:
 int i = 1;
 int& ir = i; // reference to int
 int* ip = &i; // pointer to int
 int*& ip2 = ip; // reference to pointer to int
                 // ip2 is another name for ip
 ir++; // i = 2
 (*ip)++; // i = 3
 (*ip2)++; // i = 4
like int and reference to int, we can have pointer to int and
reference to pointer to int.
About your code:
 1. To avoid memory leak, use free(s) when you don't need
    to s anymore.
 2. You can't use both functions in your code:
    char* s = NULL;
    fun(s); // ambiguous call to overloaded function.

Regards,
  -- Saeed Amrollahi

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