Qt5+MSVC2015 32位編譯器報錯: qalgorithms.h: error C3615 不會生成常數表達式

這個是Qt的Bug，解決方法是按下面說明修改qalgorithms.h文件

index 1a03bfa..b658d8a 100644 (file)
--- a/src/corelib/tools/qalgorithms.h
+++ b/src/corelib/tools/qalgorithms.h
@@ -590,6 +590,7 @@ Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) Q_DECL_NO
 }
 #elif defined(Q_CC_MSVC) && !defined(Q_OS_WINCE) && !defined(Q_PROCESSOR_ARM)
 #define QT_POPCOUNT_CONSTEXPR
+#define QT_POPCOUNT_RELAXED_CONSTEXPR
 #define QT_HAS_BUILTIN_CTZ
 Q_ALWAYS_INLINE unsigned long qt_builtin_ctz(quint32 val)
 {
@@ -676,6 +677,7 @@ Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) Q_DECL_NOTHROW
 
 #ifndef QT_POPCOUNT_CONSTEXPR
 #define QT_POPCOUNT_CONSTEXPR Q_DECL_CONSTEXPR
+#define QT_POPCOUNT_RELAXED_CONSTEXPR Q_DECL_RELAXED_CONSTEXPR
 #endif
 
 } //namespace QAlgorithmsPrivate
@@ -819,7 +821,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint32 v) Q_DECL_NOT
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL_NOTHROW
 {
 #if defined(QT_HAS_BUILTIN_CLZ)
     return v ? QAlgorithmsPrivate::qt_builtin_clz(v)-24U : 8U;
@@ -831,7 +833,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL_NOTH
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DECL_NOTHROW
 {
 #if defined(QT_HAS_BUILTIN_CLZS)
     return v ? QAlgorithmsPrivate::qt_builtin_clzs(v) : 16U;
@@ -844,7 +846,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DECL_NOT
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) Q_DECL_NOTHROW
 {
 #if defined(QT_HAS_BUILTIN_CLZLL)
     return v ? QAlgorithmsPrivate::qt_builtin_clzll(v) : 64U;
@@ -859,7 +861,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) Q_DECL_NOT
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(unsigned long v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(unsigned long v) Q_DECL_NOTHROW
 {
     return qCountLeadingZeroBits(QIntegerForSizeof<long>::Unsigned(v));
 }