Re: Returning a Struct from a Function

On May 12, 6:59 pm, Erik Wikstr=F6m <Erik-wikst...@[EMAIL PROTECTED]
> wrote:
> On 2008-05-12 18:42, Stefan Ram wrote:

> > =3D?UTF-8?B?RXJpayBXaWtzdHLDtm0=3D?=3D <Erik-wikst...@[EMAIL PROTECTED]
>
writes:=

> >>>>inline TwoFields ReturnMyFields(int myInt) {
> >>>>TwoFields myReturnStruct; [...]
> >>>>return myReturnStruct;
> >>const TwoFields & f =3D ReturnMyFields(v);

> >   How long will the object created with =BBTwoFields
> >   myReturnStruct;=AB live?

> >   I used to believe that its lifetime would end not later
> >   than the evaluation of the full expression
> >   =BBReturnMyFields(v)=AB or even when the control is leaving
> >   the block containing its declaration.

> When you bind a tem****ary to a const reference the lifetime of
> the tem****ary is extended to last as long as the reference.

That can easily be misunderstood (and often is).  Formally, the
rule is when the initialization expression of a reference is a
tem****ary, the lifetime of the tem****ary is extended to
correspond to the lifetime of that reference.  Which isn't quite
the same thing.

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James Kanze (GABI Software)             email:james.kanze@[EMAIL PROTECTED]
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