Temporaries bind to const reference

[kaede]

Hi all,

I would like to know if the following code is valid and not
ill-formed.

Data getData()
{
return Data(1, 2, 3);
}

void processData(con st Data& data)
{
// ... work with data ...
}


// ... in some code somewhere ...
processData( getData() );

Will this const reference initialized with getData() [temporaries]
make that temporary value live for the lifetime of the reference
itself?

Thanks,
Kaede

[Kevin Goodsell]

Re: Temporaries bind to const reference

kaede wrote:
[color=blue]
> Hi all,
>
> I would like to know if the following code is valid and not
> ill-formed.
>
> Data getData()
> {
> return Data(1, 2, 3);
> }
>
> void processData(con st Data& data)
> {
> // ... work with data ...
> }
>
>
> // ... in some code somewhere ...
> processData( getData() );[/color]

The code is valid (as far as I can tell - it's incomplete, after all).
[color=blue]
>
> Will this const reference initialized with getData() [temporaries]
> make that temporary value live for the lifetime of the reference
> itself?[/color]

I don't think that's precisely correct. Temporaries (usually) live until
the end of the full expression in which they are created. There are
exceptions to this, but I don't believe they apply here. In this case,
the full expression ends *after* the call to processData() returns,
therefore it has nothing to do with references - that temporary would
live until the function completed whether you used a reference or not.

-Kevin
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