references or values?

[Qiieha]

Hi,
a trivial Question to you:

What's better style:
this

class Test{
private: 
        QString one;
        QString two;
 
public:
       Text(const QString& one,const QString& two);
}
 
//cpp
 
Test::Test(const QString& one,const QString& two) :
       one(one),
       two(two)
{
}

class Test{
private: 
        QString one;
        QString two;

public:
       Text(const QString& one,const QString& two);
}

//cpp

Test::Test(const QString& one,const QString& two) :
       one(one),
       two(two)
{
}

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or that:

class Test{
private: 
        QString one;
        QString two;
 
public:
       Text(QString one, QString two);
}
 
//cpp
 
Test::Test(QString one,QString two) :
       one(one),
       two(two)
{
}

class Test{
private: 
        QString one;
        QString two;

public:
       Text(QString one, QString two);
}

//cpp

Test::Test(QString one,QString two) :
       one(one),
       two(two)
{
}

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and what's are the advantages and disatvantages?

I prefer the first option, because it looks like more performance.. Am I right?

thanks

[anda_skoa]

I would use the first one because it fits better into the overall coding style used by Qt.

Cheers,
_

[RSX]

The first one is actually more like general C++ coding style, second is used by Qt.

You can read about it here: http://qt-project.org/doc/qt-4.8/implicit-sharing.html

[Lykurg]

I would use both because they are not really comparable. Will say: I would use

const QString &one

const QString &one

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and not

const QString one

const QString one

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if they should not be changeable, but I would use

QString one

QString one

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and not

QString &one

QString &one

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if they should be changeable. (Because Implicit Sharing is cheap.)

[Qiieha]

thank u guys.
this is very good to know =)