Qt a nonstatic member reference must be relative to a specific object - qt

Question

I have a function which calls emitResult after loading data from file.
bool IpResolver::ResolvedInfo::load(QTextStream &in)
{
ResolvedInfo rf;
while (!in.atEnd())
{
QString line = in.readLine();
QStringList list = line.split(' ');
list[0] = rf.country;
list[1] = rf.ip;
if (rf.ip.isEmpty() == false)
{
emitResult(rf);
}
}
}
So here is declaration of emitResult:
private:
void emitResult(const ResolvedInfo &data);
And it gives me this error:
a nonstatic member reference must be relative to a specific object
No idea what should I do.

Answer 1

emitResult is a non-static member function of IpResolver, I presume. Yet you're calling it without any instance, from a subclass IpResolver::ResolvedInfo. Remember that just because the ResolvedInfo is a subclass, doesn't make it special in any other way. Specifically, if it doesn't hold a reference to the instance of the parent class, it won't work the way you expect it to.
There are two general ways to fix your issue:
You can pass a reference to IpResolver to the ResolvedInfo constructor, and retain the reference in the ResolvedInfo instance:
class IpResolver {
class ResolvedInfo {
IpResolver & q;
public:
ResolvedInfo(IpResolver & q) : q(q) { ... }
static bool load(QTextStream &in) {
ResolvedInfo rf;
while (!in.atEnd())
{
QString line = in.readLine();
QStringList list = line.split(' ');
list[0] = rf.country;
list[1] = rf.ip;
if (!rf.ip.isEmpty())
q.emitResult(rf);
}
}
};
void emitResult(const ResolvedInfo &);
...
};
Or you can make the emitResult a static method:
class IpResolver {
...
static void emitResult(const ResolvedInfo &);
};