diff options
| author | Marc Mutz <marc.mutz@kdab.com> | 2014-08-08 10:31:36 +0200 |
|---|---|---|
| committer | Oswald Buddenhagen <oswald.buddenhagen@digia.com> | 2014-08-09 09:06:16 +0200 |
| commit | e41b45f1aedf1b3fe0ca4b22226ccc23bc71ab7c (patch) | |
| tree | d64d54c7f865b19028548e8e6dceef760b9ae6a9 /src/corelib | |
| parent | 31f2b7e5911f730245cf347924d1c839fc2832a4 (diff) | |
QPair: add constexpr liberally
On templates, adding constexpr makes a given instantiation constexpr
if it can be.
This turns qMakePair(0,0), say, into a compile-time constant.
The effects on existing code are small, but exist:
$ size lib/*{-baseline,-paircexp} | sort -nr
6516727 211192 2608 6730527 66b31f lib/libQt5Widgets.so.5.4.0-baseline
6516711 211192 2608 6730511 66b30f lib/libQt5Widgets.so.5.4.0-paircexp
5373720 44492 15976 5434188 52eb4c lib/libQt5Core.so.5.4.0-baseline
5373504 44492 15976 5433972 52ea74 lib/libQt5Core.so.5.4.0-paircexp
5107206 125072 6080 5238358 4fee56 lib/libQt5Gui.so.5.4.0-baseline
5107030 125072 6080 5238182 4feda6 lib/libQt5Gui.so.5.4.0-paircexp
1341290 30180 2600 1374070 14f776 lib/libQt5Network.so.5.4.0-baseline
1341210 30180 2600 1373990 14f726 lib/libQt5Network.so.5.4.0-paircexp
# no other libraries benefit
[ChangeLog][QtCore][QPair] Can now be used in C++11 constexpr contexts.
Change-Id: I3872e6aa33a7d02a168516f4dfa7119efcac8c40
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Diffstat (limited to 'src/corelib')
| -rw-r--r-- | src/corelib/tools/qpair.h | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/corelib/tools/qpair.h b/src/corelib/tools/qpair.h index 9b8691a3d8..cfc8035a48 100644 --- a/src/corelib/tools/qpair.h +++ b/src/corelib/tools/qpair.h @@ -53,18 +53,18 @@ struct QPair typedef T1 first_type; typedef T2 second_type; - QPair() : first(), second() {} - QPair(const T1 &t1, const T2 &t2) : first(t1), second(t2) {} + Q_DECL_CONSTEXPR QPair() : first(), second() {} + Q_DECL_CONSTEXPR QPair(const T1 &t1, const T2 &t2) : first(t1), second(t2) {} // compiler-generated copy/move ctor/assignment operators are fine! template <typename TT1, typename TT2> - QPair(const QPair<TT1, TT2> &p) : first(p.first), second(p.second) {} + Q_DECL_CONSTEXPR QPair(const QPair<TT1, TT2> &p) : first(p.first), second(p.second) {} template <typename TT1, typename TT2> QPair &operator=(const QPair<TT1, TT2> &p) { first = p.first; second = p.second; return *this; } #ifdef Q_COMPILER_RVALUE_REFS template <typename TT1, typename TT2> - QPair(QPair<TT1, TT2> &&p) : first(std::move(p.first)), second(std::move(p.second)) {} + Q_DECL_CONSTEXPR QPair(QPair<TT1, TT2> &&p) : first(std::move(p.first)), second(std::move(p.second)) {} template <typename TT1, typename TT2> QPair &operator=(QPair<TT1, TT2> &&p) { first = std::move(p.first); second = std::move(p.second); return *this; } @@ -80,39 +80,39 @@ template<class T1, class T2> class QTypeInfo<QPair<T1, T2> > : public QTypeInfoMerger<QPair<T1, T2>, T1, T2> {}; // Q_DECLARE_TYPEINFO template <class T1, class T2> -Q_INLINE_TEMPLATE bool operator==(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) +Q_DECL_CONSTEXPR Q_INLINE_TEMPLATE bool operator==(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) { return p1.first == p2.first && p1.second == p2.second; } template <class T1, class T2> -Q_INLINE_TEMPLATE bool operator!=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) +Q_DECL_CONSTEXPR Q_INLINE_TEMPLATE bool operator!=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) { return !(p1 == p2); } template <class T1, class T2> -Q_INLINE_TEMPLATE bool operator<(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) +Q_DECL_CONSTEXPR Q_INLINE_TEMPLATE bool operator<(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) { return p1.first < p2.first || (!(p2.first < p1.first) && p1.second < p2.second); } template <class T1, class T2> -Q_INLINE_TEMPLATE bool operator>(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) +Q_DECL_CONSTEXPR Q_INLINE_TEMPLATE bool operator>(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) { return p2 < p1; } template <class T1, class T2> -Q_INLINE_TEMPLATE bool operator<=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) +Q_DECL_CONSTEXPR Q_INLINE_TEMPLATE bool operator<=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) { return !(p2 < p1); } template <class T1, class T2> -Q_INLINE_TEMPLATE bool operator>=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) +Q_DECL_CONSTEXPR Q_INLINE_TEMPLATE bool operator>=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) { return !(p1 < p2); } template <class T1, class T2> -Q_OUTOFLINE_TEMPLATE QPair<T1, T2> qMakePair(const T1 &x, const T2 &y) +Q_DECL_CONSTEXPR Q_OUTOFLINE_TEMPLATE QPair<T1, T2> qMakePair(const T1 &x, const T2 &y) { return QPair<T1, T2>(x, y); } |