QFlags: plaster API with Q_DECL_NOTHROW

Yes, this is necessary. The noexcept operator looks for noexcept tagging,
not at the contents of the function to determine whether to return true.

The more conditionally-noexcept functions are used, the more important it
becomes that low-level classes are correctly marked noexcept. In that, it
is like constexpr.

Change-Id: Ia1aebf9b8d73fd8164c10dfca27a710934ba79a8
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 37 insertions, 36 deletions

diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index cfe75c4eea..0b7b23e039 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -49,21 +49,21 @@ class QFlag
 {
     int i;
 public:
-    Q_DECL_CONSTEXPR inline QFlag(int ai) : i(ai) {}
-    Q_DECL_CONSTEXPR inline operator int() const { return i; }
+    Q_DECL_CONSTEXPR inline QFlag(int ai) Q_DECL_NOTHROW : i(ai) {}
+    Q_DECL_CONSTEXPR inline operator int() const Q_DECL_NOTHROW { return i; }
 
 #if !defined(Q_CC_MSVC)
     // Microsoft Visual Studio has buggy behavior when it comes to
     // unsigned enums: even if the enum is unsigned, the enum tags are
     // always signed
 #  if !defined(__LP64__) && !defined(Q_QDOC)
-    Q_DECL_CONSTEXPR inline QFlag(long ai) : i(int(ai)) {}
-    Q_DECL_CONSTEXPR inline QFlag(ulong ai) : i(int(long(ai))) {}
+    Q_DECL_CONSTEXPR inline QFlag(long ai) Q_DECL_NOTHROW : i(int(ai)) {}
+    Q_DECL_CONSTEXPR inline QFlag(ulong ai) Q_DECL_NOTHROW : i(int(long(ai))) {}
 #  endif
-    Q_DECL_CONSTEXPR inline QFlag(uint ai) : i(int(ai)) {}
-    Q_DECL_CONSTEXPR inline QFlag(short ai) : i(int(ai)) {}
-    Q_DECL_CONSTEXPR inline QFlag(ushort ai) : i(int(uint(ai))) {}
-    Q_DECL_CONSTEXPR inline operator uint() const { return uint(i); }
+    Q_DECL_CONSTEXPR inline QFlag(uint ai) Q_DECL_NOTHROW : i(int(ai)) {}
+    Q_DECL_CONSTEXPR inline QFlag(short ai) Q_DECL_NOTHROW : i(int(ai)) {}
+    Q_DECL_CONSTEXPR inline QFlag(ushort ai) Q_DECL_NOTHROW : i(int(uint(ai))) {}
+    Q_DECL_CONSTEXPR inline operator uint() const Q_DECL_NOTHROW { return uint(i); }
 #endif
 };
 Q_DECLARE_TYPEINFO(QFlag, Q_PRIMITIVE_TYPE);
@@ -72,12 +72,12 @@ class QIncompatibleFlag
 {
     int i;
 public:
-    Q_DECL_CONSTEXPR inline explicit QIncompatibleFlag(int i);
-    Q_DECL_CONSTEXPR inline operator int() const { return i; }
+    Q_DECL_CONSTEXPR inline explicit QIncompatibleFlag(int i) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR inline operator int() const Q_DECL_NOTHROW { return i; }
 };
 Q_DECLARE_TYPEINFO(QIncompatibleFlag, Q_PRIMITIVE_TYPE);
 
-Q_DECL_CONSTEXPR inline QIncompatibleFlag::QIncompatibleFlag(int ai) : i(ai) {}
+Q_DECL_CONSTEXPR inline QIncompatibleFlag::QIncompatibleFlag(int ai) Q_DECL_NOTHROW : i(ai) {}
 
 
 #ifndef Q_NO_TYPESAFE_FLAGS
@@ -108,41 +108,42 @@ public:
     inline QFlags(const QFlags &other);
     inline QFlags &operator=(const QFlags &other);
 #endif
-    Q_DECL_CONSTEXPR inline QFlags(Enum f) : i(Int(f)) {}
-    Q_DECL_CONSTEXPR inline QFlags(Zero = 0) : i(0) {}
-    Q_DECL_CONSTEXPR inline QFlags(QFlag f) : i(f) {}
+    Q_DECL_CONSTEXPR inline QFlags(Enum f) Q_DECL_NOTHROW : i(Int(f)) {}
+    Q_DECL_CONSTEXPR inline QFlags(Zero = 0) Q_DECL_NOTHROW : i(0) {}
+    Q_DECL_CONSTEXPR inline QFlags(QFlag f) Q_DECL_NOTHROW : i(f) {}
 
 #ifdef Q_COMPILER_INITIALIZER_LISTS
-    Q_DECL_CONSTEXPR inline QFlags(std::initializer_list<Enum> flags)
+    Q_DECL_CONSTEXPR inline QFlags(std::initializer_list<Enum> flags) Q_DECL_NOTHROW
         : i(initializer_list_helper(flags.begin(), flags.end())) {}
 #endif
 
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(int mask) { i &= mask; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(uint mask) { i &= mask; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(Enum mask) { i &= Int(mask); return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(QFlags f) { i |= f.i; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(Enum f) { i |= Int(f); return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(QFlags f) { i ^= f.i; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(Enum f) { i ^= Int(f); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(int mask) Q_DECL_NOTHROW { i &= mask; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(uint mask) Q_DECL_NOTHROW { i &= mask; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(Enum mask) Q_DECL_NOTHROW { i &= Int(mask); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(QFlags f) Q_DECL_NOTHROW { i |= f.i; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(Enum f) Q_DECL_NOTHROW { i |= Int(f); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(QFlags f) Q_DECL_NOTHROW { i ^= f.i; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(Enum f) Q_DECL_NOTHROW { i ^= Int(f); return *this; }
 
-    Q_DECL_CONSTEXPR  inline operator Int() const { return i; }
+    Q_DECL_CONSTEXPR inline operator Int() const Q_DECL_NOTHROW { return i; }
 
-    Q_DECL_CONSTEXPR inline QFlags operator|(QFlags f) const { return QFlags(QFlag(i | f.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator|(Enum f) const { return QFlags(QFlag(i | Int(f))); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(QFlags f) const { return QFlags(QFlag(i ^ f.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(Enum f) const { return QFlags(QFlag(i ^ Int(f))); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const { return QFlags(QFlag(i & mask)); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const { return QFlags(QFlag(i & mask)); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(Enum f) const { return QFlags(QFlag(i & Int(f))); }
-    Q_DECL_CONSTEXPR inline QFlags operator~() const { return QFlags(QFlag(~i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator|(QFlags f) const Q_DECL_NOTHROW { return QFlags(QFlag(i | f.i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator|(Enum f) const Q_DECL_NOTHROW { return QFlags(QFlag(i | Int(f))); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(QFlags f) const Q_DECL_NOTHROW { return QFlags(QFlag(i ^ f.i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(Enum f) const Q_DECL_NOTHROW { return QFlags(QFlag(i ^ Int(f))); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const Q_DECL_NOTHROW { return QFlags(QFlag(i & mask)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const Q_DECL_NOTHROW { return QFlags(QFlag(i & mask)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(Enum f) const Q_DECL_NOTHROW { return QFlags(QFlag(i & Int(f))); }
+    Q_DECL_CONSTEXPR inline QFlags operator~() const Q_DECL_NOTHROW { return QFlags(QFlag(~i)); }
 
-    Q_DECL_CONSTEXPR inline bool operator!() const { return !i; }
+    Q_DECL_CONSTEXPR inline bool operator!() const Q_DECL_NOTHROW { return !i; }
 
-    Q_DECL_CONSTEXPR inline bool testFlag(Enum f) const { return (i & Int(f)) == Int(f) && (Int(f) != 0 || i == Int(f) ); }
+    Q_DECL_CONSTEXPR inline bool testFlag(Enum f) const Q_DECL_NOTHROW { return (i & Int(f)) == Int(f) && (Int(f) != 0 || i == Int(f) ); }
 private:
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     Q_DECL_CONSTEXPR static inline Int initializer_list_helper(typename std::initializer_list<Enum>::const_iterator it,
                                                                typename std::initializer_list<Enum>::const_iterator end)
+    Q_DECL_NOTHROW
     {
         return (it == end ? Int(0) : (Int(*it) | initializer_list_helper(it + 1, end)));
     }
@@ -155,13 +156,13 @@ private:
 typedef QFlags<Enum> Flags;
 
 #define Q_DECLARE_INCOMPATIBLE_FLAGS(Flags) \
-Q_DECL_CONSTEXPR inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) \
+Q_DECL_CONSTEXPR inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) Q_DECL_NOTHROW \
 { return QIncompatibleFlag(int(f1) | f2); }
 
 #define Q_DECLARE_OPERATORS_FOR_FLAGS(Flags) \
-Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) \
+Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) Q_DECL_NOTHROW \
 { return QFlags<Flags::enum_type>(f1) | f2; } \
-Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) \
+Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) Q_DECL_NOTHROW \
 { return f2 | f1; } Q_DECLARE_INCOMPATIBLE_FLAGS(Flags)