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Date: Sun, 30 Jan 2011 21:02:00 -0000
Message-ID: <AANLkTi=dUr5nUGBBxzHUz=+z6Z=Fn3bxGhfj8pd30+F1@mail.gmail.com>
Subject: Re: Optimizing
From: Jonathan Wakely <jwakely.gcc@gmail.com>
To: weigelt@metux.de, gcc-help@gcc.gnu.org
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On 30 January 2011 20:40, Enrico Weigelt wrote:
> * Kalle Olavi Niemitalo <kon@iki.fi> wrote:
>
>> Although the second parameter is const void *, the language still
>> allows the function to modify the object to which that points,
>> provided that the object was not defined as const.
>
> Doesn't that defeat the whole purpose of const ?

No. http://www.gotw.ca/gotw/081.htm


> BTW: let me add another question:
>
>
> =A0 =A0const std::string str;
>
> =A0 =A0void one(const std::string s)
> =A0 =A0{
> =A0 =A0 =A0 =A0str =3D s;
> =A0 =A0}
>
> =A0 =A0void two(const char* s)
> =A0 =A0{
> =A0 =A0 =A0 =A0one(s);
> =A0 =A0}
>
> =A0 =A0void three()
> =A0 =A0{
> =A0 =A0 =A0 =A0two("hello world");
> =A0 =A0}
>
>
> What actually happens here under the hood ? Is this reliable ?
> (lifetime of the string object)

It won't compile because you assign to a const, so I don't understand
the question.