comments on KDE performance tips

[Roger Larsson]

On Saturday 18 January 2003 02:47, David Faure wrote:
> On Saturday 18 January 2003 02:16, Roger Larsson wrote:
> > 	const QString hallo =3D "hallo"; // constructor with copy
> > 	if (hallo =3D=3D hallo) ...  // only compares the string storage locat=
ion
>=20
> Nope. This calls QString::operator=3D=3D, which compares the contents.
> Please don't confuse QString and e.g. char *.
>=20

Use the source! (from qstring.cpp)

	bool operator=3D=3D( const QString &s1, const QString &s2 )
	{
	    if ( s1.unicode() =3D=3D s2.unicode() )			<=3D HERE!
		return TRUE;

	    return (s1.length() =3D=3D s2.length()) && s1.isNull() =3D=3D s2.isNul=
l() &&
			 (memcmp((char*)s1.unicode(),(char*)s2.unicode(),
			 s1.length()*sizeof(QChar)) =3D=3D 0 );
	}

This is the sequence:
a) string locations:  same? return true;
b) string length: different? return false
c) isNull: different? return false
d) compare the contents

/RogerL

=2D-=20
Roger Larsson
Skellefte=E5
Sweden