From 726fed0d67013cbfac7921d3d4613ca83406fb0f Mon Sep 17 00:00:00 2001 From: Ulf Hermann Date: Fri, 16 Oct 2015 16:52:51 +0200 Subject: Interpret precision == -128 as "shortest" double conversion Also use this for converting doubles with QVariant. We generally want exact results there, rather than adding rounding errors whenever we convert. [ChangeLog][QtCore][QLocale] Added special value for double conversion precision to get shortest accurate representation. Change-Id: I905b8a103f39adf31d24b6ce2c8a283cf271b597 Reviewed-by: Lars Knoll --- src/corelib/kernel/qvariant.cpp | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) (limited to 'src/corelib/kernel') diff --git a/src/corelib/kernel/qvariant.cpp b/src/corelib/kernel/qvariant.cpp index fdcbdb1c45..1e755cf5d8 100644 --- a/src/corelib/kernel/qvariant.cpp +++ b/src/corelib/kernel/qvariant.cpp @@ -56,6 +56,7 @@ #include "qbytearraylist.h" #endif #include "private/qvariant_p.h" +#include "private/qlocale_p.h" #include "qmetatype_p.h" #include @@ -71,18 +72,6 @@ QT_BEGIN_NAMESPACE -#ifndef DBL_MANT_DIG -# define DBL_MANT_DIG 53 -#endif -#ifndef FLT_MANT_DIG -# define FLT_MANT_DIG 24 -#endif - -const int log10_2_10000 = 30103; // log10(2) * 100000 -// same as C++11 std::numeric_limits::max_digits10 -const int max_digits10_double = (DBL_MANT_DIG * log10_2_10000) / 100000 + 2; -const int max_digits10_float = (FLT_MANT_DIG * log10_2_10000) / 100000 + 2; - namespace { class HandlersManager { @@ -433,10 +422,10 @@ static bool convert(const QVariant::Private *d, int t, void *result, bool *ok) *str = QString::number(qMetaTypeUNumber(d)); break; case QMetaType::Float: - *str = QString::number(d->data.f, 'g', max_digits10_float); + *str = QString::number(d->data.f, 'g', QLocale::FloatingPointShortest); break; case QVariant::Double: - *str = QString::number(d->data.d, 'g', max_digits10_double); + *str = QString::number(d->data.d, 'g', QLocale::FloatingPointShortest); break; #if !defined(QT_NO_DATESTRING) case QVariant::Date: @@ -625,10 +614,10 @@ static bool convert(const QVariant::Private *d, int t, void *result, bool *ok) *ba = v_cast(d)->toUtf8(); break; case QVariant::Double: - *ba = QByteArray::number(d->data.d, 'g', max_digits10_double); + *ba = QByteArray::number(d->data.d, 'g', QLocale::FloatingPointShortest); break; case QMetaType::Float: - *ba = QByteArray::number(d->data.f, 'g', max_digits10_float); + *ba = QByteArray::number(d->data.f, 'g', QLocale::FloatingPointShortest); break; case QMetaType::Char: case QMetaType::SChar: -- cgit v1.2.3