Replace Q_DECL_NOEXCEPT with noexcept in corelib

In preparation of Qt6 move away from pre-C++11 macros.

Change-Id: I44126693c20c18eca5620caab4f7e746218e0ce3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

14 files changed, 145 insertions, 145 deletions

diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index 6aa6850c69..65f4892472 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -54,21 +54,21 @@ class QFlag
 {
     int i;
 public:
-    Q_DECL_CONSTEXPR inline QFlag(int value) Q_DECL_NOTHROW : i(value) {}
-    Q_DECL_CONSTEXPR inline operator int() const Q_DECL_NOTHROW { return i; }
+    Q_DECL_CONSTEXPR inline QFlag(int value) noexcept : i(value) {}
+    Q_DECL_CONSTEXPR inline operator int() const noexcept { 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_CLANG_QDOC)
-    Q_DECL_CONSTEXPR inline QFlag(long value) Q_DECL_NOTHROW : i(int(value)) {}
-    Q_DECL_CONSTEXPR inline QFlag(ulong value) Q_DECL_NOTHROW : i(int(long(value))) {}
+    Q_DECL_CONSTEXPR inline QFlag(long value) noexcept : i(int(value)) {}
+    Q_DECL_CONSTEXPR inline QFlag(ulong value) noexcept : i(int(long(value))) {}
 #  endif
-    Q_DECL_CONSTEXPR inline QFlag(uint value) Q_DECL_NOTHROW : i(int(value)) {}
-    Q_DECL_CONSTEXPR inline QFlag(short value) Q_DECL_NOTHROW : i(int(value)) {}
-    Q_DECL_CONSTEXPR inline QFlag(ushort value) Q_DECL_NOTHROW : i(int(uint(value))) {}
-    Q_DECL_CONSTEXPR inline operator uint() const Q_DECL_NOTHROW { return uint(i); }
+    Q_DECL_CONSTEXPR inline QFlag(uint value) noexcept : i(int(value)) {}
+    Q_DECL_CONSTEXPR inline QFlag(short value) noexcept : i(int(value)) {}
+    Q_DECL_CONSTEXPR inline QFlag(ushort value) noexcept : i(int(uint(value))) {}
+    Q_DECL_CONSTEXPR inline operator uint() const noexcept { return uint(i); }
 #endif
 };
 Q_DECLARE_TYPEINFO(QFlag, Q_PRIMITIVE_TYPE);
@@ -77,12 +77,12 @@ class QIncompatibleFlag
 {
     int i;
 public:
-    Q_DECL_CONSTEXPR inline explicit QIncompatibleFlag(int i) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline operator int() const Q_DECL_NOTHROW { return i; }
+    Q_DECL_CONSTEXPR inline explicit QIncompatibleFlag(int i) noexcept;
+    Q_DECL_CONSTEXPR inline operator int() const noexcept { return i; }
 };
 Q_DECLARE_TYPEINFO(QIncompatibleFlag, Q_PRIMITIVE_TYPE);
 
-Q_DECL_CONSTEXPR inline QIncompatibleFlag::QIncompatibleFlag(int value) Q_DECL_NOTHROW : i(value) {}
+Q_DECL_CONSTEXPR inline QIncompatibleFlag::QIncompatibleFlag(int value) noexcept : i(value) {}
 
 
 #ifndef Q_NO_TYPESAFE_FLAGS
@@ -117,38 +117,38 @@ public:
     Q_DECL_CONSTEXPR inline QFlags(const QFlags &other);
     Q_DECL_CONSTEXPR inline QFlags &operator=(const QFlags &other);
 #endif
-    Q_DECL_CONSTEXPR inline QFlags(Enum flags) Q_DECL_NOTHROW : i(Int(flags)) {}
-    Q_DECL_CONSTEXPR inline QFlags(Zero = nullptr) Q_DECL_NOTHROW : i(0) {}
-    Q_DECL_CONSTEXPR inline QFlags(QFlag flag) Q_DECL_NOTHROW : i(flag) {}
+    Q_DECL_CONSTEXPR inline QFlags(Enum flags) noexcept : i(Int(flags)) {}
+    Q_DECL_CONSTEXPR inline QFlags(Zero = nullptr) noexcept : i(0) {}
+    Q_DECL_CONSTEXPR inline QFlags(QFlag flag) noexcept : i(flag) {}
 
 #ifdef Q_COMPILER_INITIALIZER_LISTS
-    Q_DECL_CONSTEXPR inline QFlags(std::initializer_list<Enum> flags) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR inline QFlags(std::initializer_list<Enum> flags) noexcept
         : i(initializer_list_helper(flags.begin(), flags.end())) {}
 #endif
 
-    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 other) Q_DECL_NOTHROW { i |= other.i; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(Enum other) Q_DECL_NOTHROW { i |= Int(other); return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(QFlags other) Q_DECL_NOTHROW { i ^= other.i; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(Enum other) Q_DECL_NOTHROW { i ^= Int(other); return *this; }
-
-    Q_DECL_CONSTEXPR inline operator Int() const Q_DECL_NOTHROW { return i; }
-
-    Q_DECL_CONSTEXPR inline QFlags operator|(QFlags other) const Q_DECL_NOTHROW { return QFlags(QFlag(i | other.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator|(Enum other) const Q_DECL_NOTHROW { return QFlags(QFlag(i | Int(other))); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(QFlags other) const Q_DECL_NOTHROW { return QFlags(QFlag(i ^ other.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(Enum other) const Q_DECL_NOTHROW { return QFlags(QFlag(i ^ Int(other))); }
-    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 other) const Q_DECL_NOTHROW { return QFlags(QFlag(i & Int(other))); }
-    Q_DECL_CONSTEXPR inline QFlags operator~() const Q_DECL_NOTHROW { return QFlags(QFlag(~i)); }
-
-    Q_DECL_CONSTEXPR inline bool operator!() const Q_DECL_NOTHROW { return !i; }
-
-    Q_DECL_CONSTEXPR inline bool testFlag(Enum flag) const Q_DECL_NOTHROW { return (i & Int(flag)) == Int(flag) && (Int(flag) != 0 || i == Int(flag) ); }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &setFlag(Enum flag, bool on = true) Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(int mask) noexcept { i &= mask; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(uint mask) noexcept { i &= mask; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(Enum mask) noexcept { i &= Int(mask); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(QFlags other) noexcept { i |= other.i; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(Enum other) noexcept { i |= Int(other); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(QFlags other) noexcept { i ^= other.i; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(Enum other) noexcept { i ^= Int(other); return *this; }
+
+    Q_DECL_CONSTEXPR inline operator Int() const noexcept { return i; }
+
+    Q_DECL_CONSTEXPR inline QFlags operator|(QFlags other) const noexcept { return QFlags(QFlag(i | other.i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator|(Enum other) const noexcept { return QFlags(QFlag(i | Int(other))); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(QFlags other) const noexcept { return QFlags(QFlag(i ^ other.i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(Enum other) const noexcept { return QFlags(QFlag(i ^ Int(other))); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const noexcept { return QFlags(QFlag(i & mask)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const noexcept { return QFlags(QFlag(i & mask)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(Enum other) const noexcept { return QFlags(QFlag(i & Int(other))); }
+    Q_DECL_CONSTEXPR inline QFlags operator~() const noexcept { return QFlags(QFlag(~i)); }
+
+    Q_DECL_CONSTEXPR inline bool operator!() const noexcept { return !i; }
+
+    Q_DECL_CONSTEXPR inline bool testFlag(Enum flag) const noexcept { return (i & Int(flag)) == Int(flag) && (Int(flag) != 0 || i == Int(flag) ); }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &setFlag(Enum flag, bool on = true) noexcept
     {
         return on ? (*this |= flag) : (*this &= ~Int(flag));
     }
@@ -157,7 +157,7 @@ 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
+    noexcept
     {
         return (it == end ? Int(0) : (Int(*it) | initializer_list_helper(it + 1, end)));
     }
@@ -172,13 +172,13 @@ typedef QFlags<Enum> Flags;
 #endif
 
 #define Q_DECLARE_INCOMPATIBLE_FLAGS(Flags) \
-Q_DECL_CONSTEXPR inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) Q_DECL_NOTHROW \
+Q_DECL_CONSTEXPR inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) noexcept \
 { 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_NOTHROW \
+Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) noexcept \
 { 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_NOTHROW \
+Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
 { return f2 | f1; } Q_DECLARE_INCOMPATIBLE_FLAGS(Flags)
 
 
diff --git a/src/corelib/global/qfloat16.cpp b/src/corelib/global/qfloat16.cpp
index 110d7c4d7c..680268c59b 100644
--- a/src/corelib/global/qfloat16.cpp
+++ b/src/corelib/global/qfloat16.cpp
@@ -132,8 +132,8 @@ extern "C" {
 #  define f16cextern    extern
 #endif
 
-f16cextern void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q_DECL_NOTHROW;
-f16cextern void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) Q_DECL_NOTHROW;
+f16cextern void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) noexcept;
+f16cextern void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) noexcept;
 
 #undef f16cextern
 }
@@ -144,7 +144,7 @@ static inline bool hasFastF16()
     return true;
 }
 
-static void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q_DECL_NOTHROW
+static void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) noexcept
 {
     __fp16 *out_f16 = reinterpret_cast<__fp16 *>(out);
     qsizetype i = 0;
@@ -154,7 +154,7 @@ static void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q
         out_f16[i] = __fp16(in[i]);
 }
 
-static void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) Q_DECL_NOTHROW
+static void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) noexcept
 {
     const __fp16 *in_f16 = reinterpret_cast<const __fp16 *>(in);
     qsizetype i = 0;
@@ -169,12 +169,12 @@ static inline bool hasFastF16()
     return false;
 }
 
-static void qFloatToFloat16_fast(quint16 *, const float *, qsizetype) Q_DECL_NOTHROW
+static void qFloatToFloat16_fast(quint16 *, const float *, qsizetype) noexcept
 {
     Q_UNREACHABLE();
 }
 
-static void qFloatFromFloat16_fast(float *, const quint16 *, qsizetype) Q_DECL_NOTHROW
+static void qFloatFromFloat16_fast(float *, const quint16 *, qsizetype) noexcept
 {
     Q_UNREACHABLE();
 }
@@ -186,7 +186,7 @@ static void qFloatFromFloat16_fast(float *, const quint16 *, qsizetype) Q_DECL_N
     Converts \a len floats from \a in to qfloat16 and stores them in \a out.
     Both \a in and \a out must have \a len allocated entries.
 */
-Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len) Q_DECL_NOTHROW
+Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len) noexcept
 {
     if (hasFastF16())
         return qFloatToFloat16_fast(reinterpret_cast<quint16 *>(out), in, len);
@@ -202,7 +202,7 @@ Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len
     Converts \a len qfloat16 from \a in to floats and stores them in \a out.
     Both \a in and \a out must have \a len allocated entries.
 */
-Q_CORE_EXPORT void qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype len) Q_DECL_NOTHROW
+Q_CORE_EXPORT void qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype len) noexcept
 {
     if (hasFastF16())
         return qFloatFromFloat16_fast(out, reinterpret_cast<const quint16 *>(in), len);
diff --git a/src/corelib/global/qfloat16.h b/src/corelib/global/qfloat16.h
index e823d0298b..243aea98be 100644
--- a/src/corelib/global/qfloat16.h
+++ b/src/corelib/global/qfloat16.h
@@ -67,14 +67,14 @@ QT_BEGIN_NAMESPACE
 class qfloat16
 {
 public:
-    constexpr inline qfloat16() Q_DECL_NOTHROW : b16(0) {}
-    inline qfloat16(float f) Q_DECL_NOTHROW;
-    inline operator float() const Q_DECL_NOTHROW;
+    constexpr inline qfloat16() noexcept : b16(0) {}
+    inline qfloat16(float f) noexcept;
+    inline operator float() const noexcept;
 
     // Support for qIs{Inf,NaN,Finite}:
-    bool isInf() const Q_DECL_NOTHROW { return ((b16 >> 8) & 0x7e) == 0x7c; }
-    bool isNaN() const Q_DECL_NOTHROW { return ((b16 >> 8) & 0x7e) == 0x7e; }
-    bool isFinite() const Q_DECL_NOTHROW { return ((b16 >> 8) & 0x7c) != 0x7c; }
+    bool isInf() const noexcept { return ((b16 >> 8) & 0x7e) == 0x7c; }
+    bool isNaN() const noexcept { return ((b16 >> 8) & 0x7e) == 0x7e; }
+    bool isFinite() const noexcept { return ((b16 >> 8) & 0x7c) != 0x7c; }
 private:
     quint16 b16;
 
@@ -84,29 +84,29 @@ private:
     Q_CORE_EXPORT static const quint32 basetable[];
     Q_CORE_EXPORT static const quint32 shifttable[];
 
-    friend bool qIsNull(qfloat16 f) Q_DECL_NOTHROW;
-    friend qfloat16 operator-(qfloat16 a) Q_DECL_NOTHROW;
+    friend bool qIsNull(qfloat16 f) noexcept;
+    friend qfloat16 operator-(qfloat16 a) noexcept;
 };
 
 Q_DECLARE_TYPEINFO(qfloat16, Q_PRIMITIVE_TYPE);
 
-Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *, const float *, qsizetype length) Q_DECL_NOTHROW;
-Q_CORE_EXPORT void qFloatFromFloat16(float *, const qfloat16 *, qsizetype length) Q_DECL_NOTHROW;
+Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *, const float *, qsizetype length) noexcept;
+Q_CORE_EXPORT void qFloatFromFloat16(float *, const qfloat16 *, qsizetype length) noexcept;
 
 // Complement qnumeric.h:
-Q_REQUIRED_RESULT inline bool qIsInf(qfloat16 f) Q_DECL_NOTHROW { return f.isInf(); }
-Q_REQUIRED_RESULT inline bool qIsNaN(qfloat16 f) Q_DECL_NOTHROW { return f.isNaN(); }
-Q_REQUIRED_RESULT inline bool qIsFinite(qfloat16 f) Q_DECL_NOTHROW { return f.isFinite(); }
+Q_REQUIRED_RESULT inline bool qIsInf(qfloat16 f) noexcept { return f.isInf(); }
+Q_REQUIRED_RESULT inline bool qIsNaN(qfloat16 f) noexcept { return f.isNaN(); }
+Q_REQUIRED_RESULT inline bool qIsFinite(qfloat16 f) noexcept { return f.isFinite(); }
 // Q_REQUIRED_RESULT quint32 qFloatDistance(qfloat16 a, qfloat16 b);
 
 // The remainder of these utility functions complement qglobal.h
-Q_REQUIRED_RESULT inline int qRound(qfloat16 d) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline int qRound(qfloat16 d) noexcept
 { return qRound(static_cast<float>(d)); }
 
-Q_REQUIRED_RESULT inline qint64 qRound64(qfloat16 d) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline qint64 qRound64(qfloat16 d) noexcept
 { return qRound64(static_cast<float>(d)); }
 
-Q_REQUIRED_RESULT inline bool qFuzzyCompare(qfloat16 p1, qfloat16 p2) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool qFuzzyCompare(qfloat16 p1, qfloat16 p2) noexcept
 {
     float f1 = static_cast<float>(p1);
     float f2 = static_cast<float>(p2);
@@ -119,19 +119,19 @@ Q_REQUIRED_RESULT inline bool qFuzzyCompare(qfloat16 p1, qfloat16 p2) Q_DECL_NOT
     return (qAbs(f1 - f2) * 102.5f <= qMin(qAbs(f1), qAbs(f2)));
 }
 
-Q_REQUIRED_RESULT inline bool qIsNull(qfloat16 f) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool qIsNull(qfloat16 f) noexcept
 {
     return (f.b16 & static_cast<quint16>(0x7fff)) == 0;
 }
 
-inline int qIntCast(qfloat16 f) Q_DECL_NOTHROW
+inline int qIntCast(qfloat16 f) noexcept
 { return int(static_cast<float>(f)); }
 
 #ifndef Q_QDOC
 QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wc99-extensions")
 QT_WARNING_DISABLE_GCC("-Wold-style-cast")
-inline qfloat16::qfloat16(float f) Q_DECL_NOTHROW
+inline qfloat16::qfloat16(float f) noexcept
 {
 #if defined(QT_COMPILER_SUPPORTS_F16C) && defined(__F16C__)
     __m128 packsingle = _mm_set_ss(f);
@@ -149,7 +149,7 @@ inline qfloat16::qfloat16(float f) Q_DECL_NOTHROW
 }
 QT_WARNING_POP
 
-inline qfloat16::operator float() const Q_DECL_NOTHROW
+inline qfloat16::operator float() const noexcept
 {
 #if defined(QT_COMPILER_SUPPORTS_F16C) && defined(__F16C__)
     __m128i packhalf = _mm_cvtsi32_si128(b16);
@@ -169,23 +169,23 @@ inline qfloat16::operator float() const Q_DECL_NOTHROW
 }
 #endif
 
-inline qfloat16 operator-(qfloat16 a) Q_DECL_NOTHROW
+inline qfloat16 operator-(qfloat16 a) noexcept
 {
     qfloat16 f;
     f.b16 = a.b16 ^ quint16(0x8000);
     return f;
 }
 
-inline qfloat16 operator+(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) + static_cast<float>(b)); }
-inline qfloat16 operator-(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) - static_cast<float>(b)); }
-inline qfloat16 operator*(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) * static_cast<float>(b)); }
-inline qfloat16 operator/(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) / static_cast<float>(b)); }
+inline qfloat16 operator+(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) + static_cast<float>(b)); }
+inline qfloat16 operator-(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) - static_cast<float>(b)); }
+inline qfloat16 operator*(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) * static_cast<float>(b)); }
+inline qfloat16 operator/(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) / static_cast<float>(b)); }
 
 #define QF16_MAKE_ARITH_OP_FP(FP, OP) \
-    inline FP operator OP(qfloat16 lhs, FP rhs) Q_DECL_NOTHROW { return static_cast<FP>(lhs) OP rhs; } \
-    inline FP operator OP(FP lhs, qfloat16 rhs) Q_DECL_NOTHROW { return lhs OP static_cast<FP>(rhs); }
+    inline FP operator OP(qfloat16 lhs, FP rhs) noexcept { return static_cast<FP>(lhs) OP rhs; } \
+    inline FP operator OP(FP lhs, qfloat16 rhs) noexcept { return lhs OP static_cast<FP>(rhs); }
 #define QF16_MAKE_ARITH_OP_EQ_FP(FP, OP_EQ, OP) \
-    inline qfloat16& operator OP_EQ(qfloat16& lhs, FP rhs) Q_DECL_NOTHROW \
+    inline qfloat16& operator OP_EQ(qfloat16& lhs, FP rhs) noexcept \
     { lhs = qfloat16(float(static_cast<FP>(lhs) OP rhs)); return lhs; }
 #define QF16_MAKE_ARITH_OP(FP) \
     QF16_MAKE_ARITH_OP_FP(FP, +) \
@@ -203,8 +203,8 @@ QF16_MAKE_ARITH_OP(float)
 #undef QF16_MAKE_ARITH_OP_FP
 
 #define QF16_MAKE_ARITH_OP_INT(OP) \
-    inline double operator OP(qfloat16 lhs, int rhs) Q_DECL_NOTHROW { return static_cast<double>(lhs) OP rhs; } \
-    inline double operator OP(int lhs, qfloat16 rhs) Q_DECL_NOTHROW { return lhs OP static_cast<double>(rhs); }
+    inline double operator OP(qfloat16 lhs, int rhs) noexcept { return static_cast<double>(lhs) OP rhs; } \
+    inline double operator OP(int lhs, qfloat16 rhs) noexcept { return lhs OP static_cast<double>(rhs); }
 QF16_MAKE_ARITH_OP_INT(+)
 QF16_MAKE_ARITH_OP_INT(-)
 QF16_MAKE_ARITH_OP_INT(*)
@@ -215,16 +215,16 @@ QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wfloat-equal")
 QT_WARNING_DISABLE_GCC("-Wfloat-equal")
 
-inline bool operator>(qfloat16 a, qfloat16 b)  Q_DECL_NOTHROW { return static_cast<float>(a) >  static_cast<float>(b); }
-inline bool operator<(qfloat16 a, qfloat16 b)  Q_DECL_NOTHROW { return static_cast<float>(a) <  static_cast<float>(b); }
-inline bool operator>=(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) >= static_cast<float>(b); }
-inline bool operator<=(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) <= static_cast<float>(b); }
-inline bool operator==(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) == static_cast<float>(b); }
-inline bool operator!=(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) != static_cast<float>(b); }
+inline bool operator>(qfloat16 a, qfloat16 b)  noexcept { return static_cast<float>(a) >  static_cast<float>(b); }
+inline bool operator<(qfloat16 a, qfloat16 b)  noexcept { return static_cast<float>(a) <  static_cast<float>(b); }
+inline bool operator>=(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) >= static_cast<float>(b); }
+inline bool operator<=(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) <= static_cast<float>(b); }
+inline bool operator==(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) == static_cast<float>(b); }
+inline bool operator!=(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) != static_cast<float>(b); }
 
 #define QF16_MAKE_BOOL_OP_FP(FP, OP) \
-    inline bool operator OP(qfloat16 lhs, FP rhs) Q_DECL_NOTHROW { return static_cast<FP>(lhs) OP rhs; } \
-    inline bool operator OP(FP lhs, qfloat16 rhs) Q_DECL_NOTHROW { return lhs OP static_cast<FP>(rhs); }
+    inline bool operator OP(qfloat16 lhs, FP rhs) noexcept { return static_cast<FP>(lhs) OP rhs; } \
+    inline bool operator OP(FP lhs, qfloat16 rhs) noexcept { return lhs OP static_cast<FP>(rhs); }
 #define QF16_MAKE_BOOL_OP(FP) \
     QF16_MAKE_BOOL_OP_FP(FP, <) \
     QF16_MAKE_BOOL_OP_FP(FP, >) \
@@ -239,8 +239,8 @@ QF16_MAKE_BOOL_OP(float)
 #undef QF16_MAKE_BOOL_OP_FP
 
 #define QF16_MAKE_BOOL_OP_INT(OP) \
-    inline bool operator OP(qfloat16 a, int b) Q_DECL_NOTHROW { return static_cast<float>(a) OP b; } \
-    inline bool operator OP(int a, qfloat16 b) Q_DECL_NOTHROW { return a OP static_cast<float>(b); }
+    inline bool operator OP(qfloat16 a, int b) noexcept { return static_cast<float>(a) OP b; } \
+    inline bool operator OP(int a, qfloat16 b) noexcept { return a OP static_cast<float>(b); }
 QF16_MAKE_BOOL_OP_INT(>)
 QF16_MAKE_BOOL_OP_INT(<)
 QF16_MAKE_BOOL_OP_INT(>=)
@@ -254,7 +254,7 @@ QT_WARNING_POP
 /*!
   \internal
 */
-Q_REQUIRED_RESULT inline bool qFuzzyIsNull(qfloat16 f) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool qFuzzyIsNull(qfloat16 f) noexcept
 {
     return qAbs(static_cast<float>(f)) <= 0.001f;
 }
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 7879109930..d95064af27 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -1147,12 +1147,12 @@ Q_STATIC_ASSERT((std::is_same<qsizetype, qptrdiff>::value));
     \sa QT_VERSION_STR, QLibraryInfo::version()
 */
 
-const char *qVersion() Q_DECL_NOTHROW
+const char *qVersion() noexcept
 {
     return QT_VERSION_STR;
 }
 
-bool qSharedBuild() Q_DECL_NOTHROW
+bool qSharedBuild() noexcept
 {
 #ifdef QT_SHARED
     return true;
@@ -3206,7 +3206,7 @@ QByteArray QSysInfo::bootUniqueId()
     The Q_CHECK_PTR macro calls this function if an allocation check
     fails.
 */
-void qt_check_pointer(const char *n, int l) Q_DECL_NOTHROW
+void qt_check_pointer(const char *n, int l) noexcept
 {
     // make separate printing calls so that the first one may flush;
     // the second one could want to allocate memory (fputs prints a
@@ -3233,7 +3233,7 @@ void qBadAlloc()
    Allows you to call std::terminate() without including <exception>.
    Called internally from QT_TERMINATE_ON_EXCEPTION
 */
-Q_NORETURN void qTerminate() Q_DECL_NOTHROW
+Q_NORETURN void qTerminate() noexcept
 {
     std::terminate();
 }
@@ -3242,7 +3242,7 @@ Q_NORETURN void qTerminate() Q_DECL_NOTHROW
 /*
   The Q_ASSERT macro calls this function when the test fails.
 */
-void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW
+void qt_assert(const char *assertion, const char *file, int line) noexcept
 {
     QMessageLogger(file, line, nullptr).fatal("ASSERT: \"%s\" in file %s, line %d", assertion, file, line);
 }
@@ -3250,7 +3250,7 @@ void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW
 /*
   The Q_ASSERT_X macro calls this function when the test fails.
 */
-void qt_assert_x(const char *where, const char *what, const char *file, int line) Q_DECL_NOTHROW
+void qt_assert_x(const char *where, const char *what, const char *file, int line) noexcept
 {
     QMessageLogger(file, line, nullptr).fatal("ASSERT failure in %s: \"%s\", file %s, line %d", where, what, file, line);
 }
@@ -3457,7 +3457,7 @@ QString qEnvironmentVariable(const char *varName)
 
     \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsSet()
 */
-bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT
+bool qEnvironmentVariableIsEmpty(const char *varName) noexcept
 {
     QMutexLocker locker(&environmentMutex);
 #ifdef Q_CC_MSVC
@@ -3492,7 +3492,7 @@ bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT
 
     \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsSet()
 */
-int qEnvironmentVariableIntValue(const char *varName, bool *ok) Q_DECL_NOEXCEPT
+int qEnvironmentVariableIntValue(const char *varName, bool *ok) noexcept
 {
     static const int NumBinaryDigitsPerOctalDigit = 3;
     static const int MaxDigitsForOctalInt =
@@ -3561,7 +3561,7 @@ int qEnvironmentVariableIntValue(const char *varName, bool *ok) Q_DECL_NOEXCEPT
 
     \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsEmpty()
 */
-bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT
+bool qEnvironmentVariableIsSet(const char *varName) noexcept
 {
     QMutexLocker locker(&environmentMutex);
 #ifdef Q_CC_MSVC
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h
index 223ebbcabe..f62d078035 100644
--- a/src/corelib/global/qglobal.h
+++ b/src/corelib/global/qglobal.h
@@ -411,7 +411,7 @@ typedef double qreal;
 #if !defined(QT_NAMESPACE) && defined(__cplusplus) && !defined(Q_QDOC)
 extern "C"
 #endif
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION const char *qVersion(void) Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION const char *qVersion(void) Q_DECL_NOEXCEPT;
 
 #if defined(__cplusplus)
 
@@ -730,7 +730,7 @@ inline void qt_noop(void) {}
 #  define QT_CATCH(A) catch (A)
 #  define QT_THROW(A) throw A
 #  define QT_RETHROW throw
-Q_NORETURN Q_DECL_COLD_FUNCTION Q_CORE_EXPORT void qTerminate() Q_DECL_NOTHROW;
+Q_NORETURN Q_DECL_COLD_FUNCTION Q_CORE_EXPORT void qTerminate() noexcept;
 #  ifdef Q_COMPILER_NOEXCEPT
 #    define QT_TERMINATE_ON_EXCEPTION(expr) do { expr; } while (false)
 #  else
@@ -738,7 +738,7 @@ Q_NORETURN Q_DECL_COLD_FUNCTION Q_CORE_EXPORT void qTerminate() Q_DECL_NOTHROW;
 #  endif
 #endif
 
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION bool qSharedBuild() Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION bool qSharedBuild() noexcept;
 
 #ifndef Q_OUTOFLINE_TEMPLATE
 #  define Q_OUTOFLINE_TEMPLATE
@@ -781,7 +781,7 @@ Q_CORE_EXPORT QString qt_error_string(int errorCode = -1);
 Q_NORETURN
 #endif
 Q_DECL_COLD_FUNCTION
-Q_CORE_EXPORT void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW;
+Q_CORE_EXPORT void qt_assert(const char *assertion, const char *file, int line) noexcept;
 
 #if !defined(Q_ASSERT)
 #  if defined(QT_NO_DEBUG) && !defined(QT_FORCE_ASSERTS)
@@ -799,7 +799,7 @@ Q_CORE_EXPORT void qt_assert(const char *assertion, const char *file, int line)
 Q_NORETURN
 #endif
 Q_DECL_COLD_FUNCTION
-Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *file, int line) Q_DECL_NOTHROW;
+Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *file, int line) noexcept;
 
 #if !defined(Q_ASSERT_X)
 #  if defined(QT_NO_DEBUG) && !defined(QT_FORCE_ASSERTS)
@@ -809,7 +809,7 @@ Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *
 #  endif
 #endif
 
-Q_NORETURN Q_CORE_EXPORT void qt_check_pointer(const char *, int) Q_DECL_NOTHROW;
+Q_NORETURN Q_CORE_EXPORT void qt_check_pointer(const char *, int) noexcept;
 Q_DECL_COLD_FUNCTION
 Q_CORE_EXPORT void qBadAlloc();
 
@@ -968,7 +968,7 @@ QT_WARNING_DISABLE_MSVC(4530) /* C++ exception handler used, but unwind semantic
 
 // this adds const to non-const objects (like std::as_const)
 template <typename T>
-Q_DECL_CONSTEXPR typename std::add_const<T>::type &qAsConst(T &t) Q_DECL_NOTHROW { return t; }
+Q_DECL_CONSTEXPR typename std::add_const<T>::type &qAsConst(T &t) noexcept { return t; }
 // prevent rvalue arguments:
 template <typename T>
 void qAsConst(const T &&) Q_DECL_EQ_DELETE;
@@ -1130,11 +1130,11 @@ template <typename... Args>
 struct QNonConstOverload
 {
     template <typename R, typename T>
-    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
+    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...)) const noexcept -> decltype(ptr)
     { return ptr; }
 
     template <typename R, typename T>
-    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
+    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...)) noexcept -> decltype(ptr)
     { return ptr; }
 };
 
@@ -1142,11 +1142,11 @@ template <typename... Args>
 struct QConstOverload
 {
     template <typename R, typename T>
-    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...) const) const Q_DECL_NOTHROW -> decltype(ptr)
+    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...) const) const noexcept -> decltype(ptr)
     { return ptr; }
 
     template <typename R, typename T>
-    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...) const) Q_DECL_NOTHROW -> decltype(ptr)
+    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...) const) noexcept -> decltype(ptr)
     { return ptr; }
 };
 
@@ -1159,11 +1159,11 @@ struct QOverload : QConstOverload<Args...>, QNonConstOverload<Args...>
     using QNonConstOverload<Args...>::operator();
 
     template <typename R>
-    Q_DECL_CONSTEXPR auto operator()(R (*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
+    Q_DECL_CONSTEXPR auto operator()(R (*ptr)(Args...)) const noexcept -> decltype(ptr)
     { return ptr; }
 
     template <typename R>
-    static Q_DECL_CONSTEXPR auto of(R (*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
+    static Q_DECL_CONSTEXPR auto of(R (*ptr)(Args...)) noexcept -> decltype(ptr)
     { return ptr; }
 };
 
@@ -1184,9 +1184,9 @@ Q_CORE_EXPORT QString qEnvironmentVariable(const char *varName, const QString &d
 Q_CORE_EXPORT bool qputenv(const char *varName, const QByteArray& value);
 Q_CORE_EXPORT bool qunsetenv(const char *varName);
 
-Q_CORE_EXPORT bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT;
-Q_CORE_EXPORT bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT;
-Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=nullptr) Q_DECL_NOEXCEPT;
+Q_CORE_EXPORT bool qEnvironmentVariableIsEmpty(const char *varName) noexcept;
+Q_CORE_EXPORT bool qEnvironmentVariableIsSet(const char *varName) noexcept;
+Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=nullptr) noexcept;
 
 inline int qIntCast(double f) { return int(f); }
 inline int qIntCast(float f) { return int(f); }
diff --git a/src/corelib/global/qglobalstatic.h b/src/corelib/global/qglobalstatic.h
index 93d71cee57..6d27e3a984 100644
--- a/src/corelib/global/qglobalstatic.h
+++ b/src/corelib/global/qglobalstatic.h
@@ -79,7 +79,7 @@ enum GuardValues {
     Q_GLOBAL_STATIC_INTERNAL_DECORATION Type *innerFunction()   \
     {                                                           \
         struct HolderBase {                                     \
-            ~HolderBase() Q_DECL_NOTHROW                        \
+            ~HolderBase() noexcept                        \
             { if (guard.load() == QtGlobalStatic::Initialized)  \
                   guard.store(QtGlobalStatic::Destroyed); }     \
         };                                                      \
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index 88cc5b0b01..c3eb469767 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -350,7 +350,7 @@ QLibraryInfo::buildDate()
   \since 5.3
 */
 
-const char *QLibraryInfo::build() Q_DECL_NOTHROW
+const char *QLibraryInfo::build() noexcept
 {
     return QT_BUILD_STR;
 }
@@ -377,7 +377,7 @@ QLibraryInfo::isDebugBuild()
 
     \sa qVersion()
 */
-QVersionNumber QLibraryInfo::version() Q_DECL_NOTHROW
+QVersionNumber QLibraryInfo::version() noexcept
 {
     return QVersionNumber(QT_VERSION_MAJOR, QT_VERSION_MINOR, QT_VERSION_PATCH);
 }
diff --git a/src/corelib/global/qlibraryinfo.h b/src/corelib/global/qlibraryinfo.h
index 80fc5bd4fc..20fd3897f7 100644
--- a/src/corelib/global/qlibraryinfo.h
+++ b/src/corelib/global/qlibraryinfo.h
@@ -62,12 +62,12 @@ public:
 #endif // QT_DEPRECATED_SINCE(5, 5)
 #endif // datestring
 
-    static const char * build() Q_DECL_NOTHROW;
+    static const char * build() noexcept;
 
     static bool isDebugBuild();
 
 #ifndef QT_BOOTSTRAPPED
-    static QVersionNumber version() Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static QVersionNumber version() noexcept Q_DECL_CONST_FUNCTION;
 #endif
 
     enum LibraryLocation
diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp
index b2093101fa..a4d86e393b 100644
--- a/src/corelib/global/qlogging.cpp
+++ b/src/corelib/global/qlogging.cpp
@@ -346,7 +346,7 @@ using namespace QtPrivate;
 */
 
 #if defined(Q_CC_MSVC) && defined(QT_DEBUG) && defined(_DEBUG) && defined(_CRT_ERROR)
-static inline void convert_to_wchar_t_elided(wchar_t *d, size_t space, const char *s) Q_DECL_NOEXCEPT
+static inline void convert_to_wchar_t_elided(wchar_t *d, size_t space, const char *s) noexcept
 {
     size_t len = qstrlen(s);
     if (len + 1 > space) {
@@ -529,7 +529,7 @@ QDebug QMessageLogger::debug(QMessageLogger::CategoryFunction catFunc) const
 
     \sa QNoDebug, qDebug()
 */
-QNoDebug QMessageLogger::noDebug() const Q_DECL_NOTHROW
+QNoDebug QMessageLogger::noDebug() const noexcept
 {
     return QNoDebug();
 }
@@ -875,7 +875,7 @@ QDebug QMessageLogger::critical(QMessageLogger::CategoryFunction catFunc) const
 
     \sa qFatal()
 */
-void QMessageLogger::fatal(const char *msg, ...) const Q_DECL_NOTHROW
+void QMessageLogger::fatal(const char *msg, ...) const noexcept
 {
     QString message;
 
diff --git a/src/corelib/global/qlogging.h b/src/corelib/global/qlogging.h
index dded09999b..8f39780112 100644
--- a/src/corelib/global/qlogging.h
+++ b/src/corelib/global/qlogging.h
@@ -121,7 +121,7 @@ public:
     Q_NORETURN
 #endif
     Q_DECL_COLD_FUNCTION
-    void fatal(const char *msg, ...) const Q_DECL_NOTHROW Q_ATTRIBUTE_FORMAT_PRINTF(2, 3);
+    void fatal(const char *msg, ...) const noexcept Q_ATTRIBUTE_FORMAT_PRINTF(2, 3);
 
 #ifndef QT_NO_DEBUG_STREAM
     QDebug debug() const;
@@ -137,7 +137,7 @@ public:
     QDebug critical(const QLoggingCategory &cat) const;
     QDebug critical(CategoryFunction catFunc) const;
 
-    QNoDebug noDebug() const Q_DECL_NOTHROW;
+    QNoDebug noDebug() const noexcept;
 #endif // QT_NO_DEBUG_STREAM
 
 private:
diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h
index 6488426e64..610d7e4db7 100644
--- a/src/corelib/global/qnamespace.h
+++ b/src/corelib/global/qnamespace.h
@@ -50,10 +50,10 @@ QT_BEGIN_NAMESPACE
 
 #if !defined(Q_QDOC) && !defined(Q_MOC_RUN)
 struct QMetaObject;
-const QMetaObject *qt_getQtMetaObject() Q_DECL_NOEXCEPT; // defined in qobject.h (which can't be included here)
+const QMetaObject *qt_getQtMetaObject() noexcept; // defined in qobject.h (which can't be included here)
 #define QT_Q_ENUM(ENUM) \
-    inline const QMetaObject *qt_getEnumMetaObject(ENUM) Q_DECL_NOEXCEPT { return qt_getQtMetaObject(); } \
-    inline Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) Q_DECL_NOEXCEPT { return #ENUM; }
+    inline const QMetaObject *qt_getEnumMetaObject(ENUM) noexcept { return qt_getQtMetaObject(); } \
+    inline Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) noexcept { return #ENUM; }
 #define QT_Q_FLAG(ENUM) QT_Q_ENUM(ENUM)
 #else
 #define QT_Q_ENUM Q_ENUM
diff --git a/src/corelib/global/qnumeric_p.h b/src/corelib/global/qnumeric_p.h
index 56e670c477..21f9cfbef0 100644
--- a/src/corelib/global/qnumeric_p.h
+++ b/src/corelib/global/qnumeric_p.h
@@ -126,7 +126,7 @@ Q_DECL_CONST_FUNCTION static inline int fpclassify(float f) { return std::fpclas
 #endif
 }
 
-Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_inf() Q_DECL_NOEXCEPT
+Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_inf() noexcept
 {
     Q_STATIC_ASSERT_X(std::numeric_limits<double>::has_infinity,
                       "platform has no definition for infinity for type double");
@@ -134,7 +134,7 @@ Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_inf() Q_DECL_NOEX
 }
 
 // Signaling NaN
-Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_snan() Q_DECL_NOEXCEPT
+Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_snan() noexcept
 {
     Q_STATIC_ASSERT_X(std::numeric_limits<double>::has_signaling_NaN,
                       "platform has no definition for signaling NaN for type double");
@@ -142,7 +142,7 @@ Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_snan() Q_DECL_NOE
 }
 
 // Quiet NaN
-Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_qnan() Q_DECL_NOEXCEPT
+Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_qnan() noexcept
 {
     Q_STATIC_ASSERT_X(std::numeric_limits<double>::has_quiet_NaN,
                       "platform has no definition for quiet NaN for type double");
diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index 90df8653a7..fbc4222763 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -91,7 +91,7 @@ DECLSPEC_IMPORT BOOLEAN WINAPI SystemFunction036(PVOID RandomBuffer, ULONG Rando
 QT_BEGIN_NAMESPACE
 
 #if defined(Q_PROCESSOR_X86) && QT_COMPILER_SUPPORTS_HERE(RDRND)
-static qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW;
+static qsizetype qt_random_cpu(void *buffer, qsizetype count) noexcept;
 
 #  ifdef Q_PROCESSOR_X86_64
 #    define _rdrandXX_step _rdrand64_step
@@ -99,7 +99,7 @@ static qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW;
 #    define _rdrandXX_step _rdrand32_step
 #  endif
 
-static QT_FUNCTION_TARGET(RDRND) qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW
+static QT_FUNCTION_TARGET(RDRND) qsizetype qt_random_cpu(void *buffer, qsizetype count) noexcept
 {
     unsigned *ptr = reinterpret_cast<unsigned *>(buffer);
     unsigned *end = ptr + count;
@@ -134,7 +134,7 @@ enum {
 struct QRandomGenerator::SystemGenerator
 {
 #if QT_CONFIG(getentropy)
-    static qsizetype fillBuffer(void *buffer, qsizetype count) Q_DECL_NOTHROW
+    static qsizetype fillBuffer(void *buffer, qsizetype count) noexcept
     {
         // getentropy can read at most 256 bytes, so break the reading
         qsizetype read = 0;
@@ -204,13 +204,13 @@ struct QRandomGenerator::SystemGenerator
     }
 
 #elif defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
-    qsizetype fillBuffer(void *buffer, qsizetype count) Q_DECL_NOTHROW
+    qsizetype fillBuffer(void *buffer, qsizetype count) noexcept
     {
         auto RtlGenRandom = SystemFunction036;
         return RtlGenRandom(buffer, ULONG(count)) ? count: 0;
     }
 #elif defined(Q_OS_WINRT)
-    qsizetype fillBuffer(void *, qsizetype) Q_DECL_NOTHROW
+    qsizetype fillBuffer(void *, qsizetype) noexcept
     {
         // always use the fallback
         return 0;
@@ -242,7 +242,7 @@ struct QRandomGenerator::SystemGenerator
 
 #if defined(Q_OS_WIN)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) noexcept
 {
     // on Windows, rand_s is a high-quality random number generator
     // and it requires no seeding
@@ -254,14 +254,14 @@ static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
 }
 #elif QT_CONFIG(getentropy)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *, qsizetype) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *, qsizetype) noexcept
 {
     // no fallback necessary, getentropy cannot fail under normal circumstances
     Q_UNREACHABLE();
 }
 #elif defined(Q_OS_BSD4) && !defined(__GLIBC__)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) noexcept
 {
     // BSDs have arc4random(4) and these work even in chroot(2)
     arc4random_buf(ptr, left * sizeof(*ptr));
@@ -280,7 +280,7 @@ Q_NEVER_INLINE
 #ifdef Q_CC_GNU
 __attribute__((cold))   // this function is pretty big, so optimize for size
 #endif
-static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) noexcept
 {
     quint32 scratch[12];    // see element count below
     quint32 *end = scratch;
@@ -1167,7 +1167,7 @@ QRandomGenerator &QRandomGenerator::operator=(const QRandomGenerator &other)
     return *this;
 }
 
-QRandomGenerator::QRandomGenerator(std::seed_seq &sseq) Q_DECL_NOTHROW
+QRandomGenerator::QRandomGenerator(std::seed_seq &sseq) noexcept
     : type(MersenneTwister)
 {
     Q_ASSERT(this != system());
diff --git a/src/corelib/global/qrandom.h b/src/corelib/global/qrandom.h
index 46d3e0e152..2f72528266 100644
--- a/src/corelib/global/qrandom.h
+++ b/src/corelib/global/qrandom.h
@@ -68,7 +68,7 @@ public:
     QRandomGenerator(const quint32 *seedBuffer, qsizetype len)
         : QRandomGenerator(seedBuffer, seedBuffer + len)
     {}
-    Q_CORE_EXPORT QRandomGenerator(std::seed_seq &sseq) Q_DECL_NOTHROW;
+    Q_CORE_EXPORT QRandomGenerator(std::seed_seq &sseq) noexcept;
     Q_CORE_EXPORT QRandomGenerator(const quint32 *begin, const quint32 *end);
 
     // copy constructor & assignment operator (move unnecessary)
@@ -165,7 +165,7 @@ public:
     typedef quint32 result_type;
     result_type operator()() { return generate(); }
     void seed(quint32 s = 1) { *this = { s }; }
-    void seed(std::seed_seq &sseq) Q_DECL_NOTHROW { *this = { sseq }; }
+    void seed(std::seed_seq &sseq) noexcept { *this = { sseq }; }
     Q_CORE_EXPORT void discard(unsigned long long z);
     static Q_DECL_CONSTEXPR result_type min() { return std::numeric_limits<result_type>::min(); }
     static Q_DECL_CONSTEXPR result_type max() { return std::numeric_limits<result_type>::max(); }
@@ -228,7 +228,7 @@ public:
     QRandomGenerator64(const quint32 *seedBuffer, qsizetype len)
         : QRandomGenerator(seedBuffer, len)
     {}
-    QRandomGenerator64(std::seed_seq &sseq) Q_DECL_NOTHROW
+    QRandomGenerator64(std::seed_seq &sseq) noexcept
         : QRandomGenerator(sseq)
     {}
     QRandomGenerator64(const quint32 *begin, const quint32 *end)