construct wxString with NULL Topic is solved

[MoonKid]

I am not sure if I read the wxString code right. But is it possible to construct a empty wxString like that:

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wxString str(NULL);

Of course, it is dirty in this case. But generaly: is it possible?

[benedicte]

From wxWidgets documentation:
Your code corresponds to

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wxString(const wxChar* psz, size_t nLength = wxSTRING_MAXLEN)
// or
wxString(const unsigned char* psz, size_t nLength = wxSTRING_MAXLEN)

Therefore, it must be correct.

[Jorg]

Why not use wxEmptyString ?

wxString name = wxEmptyString;

It assigns a null kind of wxString to your wxString. It is more elegant then using a NULL which you do not know what exactly happens.

- Jorgen

[krzysiek_t]

And - as always - you can create empty string using the default constructor:

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wxString empty_str;

[Jorg]

Yep, but wxEmptyString is usually very handy for default arguments and returns by reference. Like;

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myfunction(int arg1, int arg2, wxString &name = wxEmptyString);

Where the last can be omitted.

Also returning after an error,

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{
  wxCHECK2(somecond == false, wxEmptyString);
  return someotherstring;
}

If wxCHECK2 fails, in debug this leaves an assertion. In release code it expands to:

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if(somecond == false)
  return wxEmptyString;

Regards,
- Jorgen

[Ryan Norton]

And there are even internal mechanics that avoid refcounting when using wxEmptyString....

[framepointer]

And make sure that you always decalare function arguments as

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const wcString &

when using wxEmptyString.

Actually it better to init strings like
wxString str(_T("")) because using the default contructor gives valgring errors : invalid read of size 1 (under wx 2.6.3).