«

Hi,

I am porting a piece of code from VC++ to linux platform. My compiler
is g++ 3.2.2. I am getting following error:

no matching function for call to A::setResponse(std::wstring)
candidates are A::setResponse(std::wstring &) ---> This is
indeed the signature

I am using this function as:

std::wstring A::getXMLStr()
{
std::wstring str = /* get a string from XML attribute */
return str;
}

A::setResponse(std::wstring &str)
{
this->response = str;
}

A::sendMsg()
{
this->setResponse(this->getXMLStr());
}

Can anybody please tell me whether this problem is becasue copy
constructor of std::wstring is explicit? Is this problem been fixed in
recent gcc? In that case in which version of gcc this problem is fixed?

Thanks and regards,
- Uday

wrote:
> Hi,
>
> I am porting a piece of code from VC++ to linux platform. My compiler
> is g++ 3.2.2. I am getting following error:
>
> no matching function for call to A::setResponse(std::wstring)
> candidates are A::setResponse(std::wstring &) ---> This is
> indeed the signature
>
> I am using this function as:
>
> std::wstring A::getXMLStr()
> {
> std::wstring str = /* get a string from XML attribute */
> return str;
> }
>
> A::setResponse(std::wstring &str)
> {
> this->response = str;
> }
>
> A::sendMsg()
> {
> this->setResponse(this->getXMLStr());
> }
>
> Can anybody please tell me whether this problem is becasue copy
> constructor of std::wstring is explicit? Is this problem been fixed in
> recent gcc? In that case in which version of gcc this problem is fixed?

This is a problem in your code, which Microsoft allowed for but
shouldn't have. You are trying to bind a temporary (the returned
wstring from A::getXMLStr()) to a non-const reference, which is
illegal. You should alter the signature for A::setResponse() to one of
these:

A::setResponse(std::wstring str) // if str changes
A::setResponse(const std::wstring& str) // if str doesn't change

Also, you probably don't need all the references to "this." It is
implied and unnecessary (except in some relatively rare circumstances
with templates).

Cheers! --M

On Wed, 07 Jun 2006 06:33:25 -0700, uday.sen wrote:

> Hi,
>
> I am porting a piece of code from VC++ to linux platform. My compiler is
> g++ 3.2.2. I am getting following error:
>
> no matching function for call to A::setResponse(std::wstring)
> candidates are A::setResponse(std::wstring &) ---> This is
> indeed the signature
>
> I am using this function as:
>
> std::wstring A::getXMLStr()
> {
> std::wstring str = /* get a string from XML attribute */ return
> str;
> }
>
> A::setResponse(std::wstring &str)
> {
> this->response = str;
> }
>
> A::sendMsg()
> {
> this->setResponse(this->getXMLStr());
> }
>
> Can anybody please tell me whether this problem is becasue copy
> constructor of std::wstring is explicit? Is this problem been fixed in
> recent gcc? In that case in which version of gcc this problem is fixed?

gcc isn't broken, VC++ is. You may not bind a temporary to a non-const
reference. The value returned by getXMLStr is a temporary string, and
setResponse takes a non-const reference to string. Looking at the code,
your setResponse doesn't ever try to modify the passed-in value, so it
should take the parameter by const-reference.

Thanks a lot. I got the point.

mlimber wrote:

> wrote:
> > Hi,
> >
> > I am porting a piece of code from VC++ to linux platform. My compiler
> > is g++ 3.2.2. I am getting following error:
> >
> > no matching function for call to A::setResponse(std::wstring)
> > candidates are A::setResponse(std::wstring &) ---> This is
> > indeed the signature
> >
> > I am using this function as:
> >
> > std::wstring A::getXMLStr()
> > {
> > std::wstring str = /* get a string from XML attribute */
> > return str;
> > }
> >
> > A::setResponse(std::wstring &str)
> > {
> > this->response = str;
> > }
> >
> > A::sendMsg()
> > {
> > this->setResponse(this->getXMLStr());
> > }
> >
> > Can anybody please tell me whether this problem is becasue copy
> > constructor of std::wstring is explicit? Is this problem been fixed in
> > recent gcc? In that case in which version of gcc this problem is fixed?
>
> This is a problem in your code, which Microsoft allowed for but
> shouldn't have. You are trying to bind a temporary (the returned
> wstring from A::getXMLStr()) to a non-const reference, which is
> illegal. You should alter the signature for A::setResponse() to one of
> these:
>
> A::setResponse(std::wstring str) // if str changes
> A::setResponse(const std::wstring& str) // if str doesn't change
>
> Also, you probably don't need all the references to "this." It is
> implied and unnecessary (except in some relatively rare circumstances
> with templates).
>
> Cheers! --M