[Development] QJsonValue (was: Re: Qt 5.2 header diff: QtCore)

[Thiago Macieira]

On terça-feira, 5 de novembro de 2013 11:44:41, Marc Mutz wrote:
> On Tuesday, November 05, 2013 01:07:32 Thiago Macieira wrote:
> > diff --git a/src/corelib/json/qjsonvalue.h b/src/corelib/json/qjsonvalue.h
> > index b8bdf55..c0ecdd2 100644
> > --- a/src/corelib/json/qjsonvalue.h
> > +++ b/src/corelib/json/qjsonvalue.h
> > 
> > @@ -79,6 +79,7 @@ public:
> >      QJsonValue(bool b);
> >      QJsonValue(double n);
> >      QJsonValue(int n);
> > 
> > +    QJsonValue(qint64 n);
> > 
> >      QJsonValue(const QString &s);
> >      QJsonValue(QLatin1String s);
> >      QJsonValue(const QJsonArray &a);
> > 
> > @@ -102,6 +103,7 @@ public:
> >      inline bool isUndefined() const { return type() == Undefined; }
> >      
> >      bool toBool(bool defaultValue = false) const;
> > 
> > +    int toInt(int defaultValue = 0) const;
> > 
> >      double toDouble(double defaultValue = 0) const;
> >      QString toString(const QString &defaultValue = QString()) const;
> >      QJsonArray toArray() const;
> > 
> > @@ -157,6 +159,7 @@ public:
> >      inline bool isUndefined() const { return type() ==
> > 
> > QJsonValue::Undefined; }
> > 
> >      inline bool toBool() const { return toValue().toBool(); }
> > 
> > +    inline int toInt() const { return toValue().toInt(); }
> > 
> >      inline double toDouble() const { return toValue().toDouble(); }
> >      inline QString toString() const { return toValue().toString(); }
> >      QJsonArray toArray() const;
> > 
> > @@ -176,7 +179,7 @@ private:
> >      uint index : 31;
> >  
> >  };
> 
> It seems there's no way to get the 64bit value back, once set with the new
> ctor.

I think that was intentional since JSON is still using ECMAScript data types, 
whose Number type is a double precision floating point. Inserting any integer 
larger than 2^52 will result in loss of precision. So this forces people to 
use the toDouble() method to get the value back.

> And isn't the new ctor going to be ambiguous?

Not more than it is. Unless you're seeing something I'm not. Can you expand 
further?

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center
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