Declaring struct/class local to a function

[dearvivekkumar]

Hi,

Is it correct to declare a class local to any function.

Suppose I have a class like :

class AnyClass
{
public:
    void FunctionA();
};

void AnyClass::FunctionA()
{
    struct CompareLess
    {
        bool operator() (const juce::String &lhs, const juce::String &rhs) const
        {
            bool retVal = false;
            int result = lhs.compareLexicographically(rhs);
            if(result < 0)
                retVal = true;
            else
                retVal = false;
        
            return retVal;
        }
    };
    std::set<juce::String, CompareLess> words;
}

Again, I working fine in for-granted Visual studio, But getting error in XCODE IDE(gcc). I'am not saying that gcc is wrong but I wants to know my mistake, what I am doing wrong?

It will be greatly appreciable if someone explain how compiler work for this piece of code?

Thanks
Vivek

[dearvivekkumar]

One more things, If I write this CompareLess struct outside this function then it's working fine!

[guestgulkan]

The (current) C++ standards documents does say that local classes aren't allowed to be
used in this way - but C++0X will remove that restriction.

So GCC is faithful to the current letter of the law so to speak.

But this restriction was always considerd too strict - See here (and numerous othr places)
http://www.informit.com/guides/content.aspx?g=cplusplus&seqNum=420