TinyCbor: port away from Q_FOREACH

Upstream change: https://github.com/intel/tinycbor/pull/238

Says it in the upstream commit message:

> Unfortunately, the container's initialization code doesn't exactly
> lend itself to making the container const (not even IILE
> (Immediately-Invoked Lambda Expression) would help here, due to the
> interdependency with len), so the idiomatic solution would be to use
> std::as_const()/qAsConst().
>
> The former is available from C++17, which we don't require, yet, and
> the latter is not available under QT_NO_AS_CONST (the default for Qt
> these days), so grab the nettle and implement a t17::as_const() that
> switches between a manual implementation of std::as_const and the
> real thing, depending on __cpp_lib_as_const. The t17 here mimicks
> the qNN (q20::remove_cvref_t/q23::forward_like/etc) mechanism used
> in Qt itself for backports, with s/q/t/ because ... _T_inyCbor.
>
> The t17 implementation is local to tst_encoder.cpp, but can easily
> be extracted into a separate header once more users emerge.

Task-number: QTBUG-115839
Change-Id: I200ae6abbb6173fa9d4b9964be66501c2145f066
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/3rdparty/tinycbor/0001-tst_Encoder-port-away-from-Q_FOREACH.patch

@@ -0,0 +1,79 @@
+From b6e2caf7452bf2b695583196fd7b346c1663d798 Mon Sep 17 00:00:00 2001
+From: Marc Mutz <marc.mutz@qt.io>
+Date: Mon, 7 Aug 2023 16:24:13 +0200
+Subject: [PATCH] tst_Encoder: port away from Q_FOREACH
+
+Qt is defaulting to QT_NO_FOREACH these days, so make sure we
+integrate nicely with downstream and fix the single Q_FOREACH/foreach
+user, in tst_encoder.cpp.
+
+Unfortunately, the container's initialization code doesn't exactly
+lend itself to making the container const (not even IILE
+(Immediately-Invoked Lambda Expression) would help here, due to the
+interdependency with `len`), so the idiomatic solution would be to use
+std::as_const()/qAsConst().
+
+The former is available from C++17, which we don't require, yet, and
+the latter is not available under QT_NO_AS_CONST (the default for Qt
+these days), so grab the nettle and implement a t17::as_const() that
+switches between a manual implementation of std::as_const and the real
+thing, depending on __cpp_lib_as_const. The `t17` here mimicks the qNN
+(q20::remove_cvref_t/q23::forward_like/etc) mechanism used in Qt
+itself for backports, with s/q/t/ because ... _T_inyCbor.
+
+The t17 implementation is local to tst_encoder.cpp, but can easily be
+extracted into a separate header once more users emerge.
+---
+ tests/encoder/encoder.pro     |  2 ++
+ tests/encoder/tst_encoder.cpp | 15 ++++++++++++++-
+ 2 files changed, 16 insertions(+), 1 deletion(-)
+
+diff --git a/tests/encoder/encoder.pro b/tests/encoder/encoder.pro
+index 62d9b7e..180f0d7 100644
+--- a/tests/encoder/encoder.pro
++++ b/tests/encoder/encoder.pro
+@@ -3,6 +3,8 @@ SOURCES += tst_encoder.cpp
+ CONFIG += testcase parallel_test c++11
+ QT = core testlib
+ 
++DEFINES += QT_NO_FOREACH QT_NO_AS_CONST
++
+ INCLUDEPATH += ../../src
+ msvc: POST_TARGETDEPS = ../../lib/tinycbor.lib
+ else: POST_TARGETDEPS += ../../lib/libtinycbor.a
+diff --git a/tests/encoder/tst_encoder.cpp b/tests/encoder/tst_encoder.cpp
+index 31c2915..61ce9c9 100644
+--- a/tests/encoder/tst_encoder.cpp
++++ b/tests/encoder/tst_encoder.cpp
+@@ -29,6 +29,19 @@
+ #include <qfloat16.h>
+ #endif
+ 
++#include <utility>
++namespace t17 {
++#ifdef __cpp_lib_as_const
++    using std::as_const;
++#else
++    template <typename T>
++    constexpr typename std::add_const<T>::type &as_const(T &t) noexcept { return t; }
++    // prevent rvalue arguments:
++    template <typename T>
++    void as_const(const T &&) = delete;
++#endif // __cpp_lib_as_const
++} // namespace t17
++
+ Q_DECLARE_METATYPE(CborError)
+ namespace QTest {
+ template<> char *toString<CborError>(const CborError &err)
+@@ -153,7 +166,7 @@ CborError encodeVariant(CborEncoder *encoder, const QVariant &v)
+             CborError err = cbor_encoder_create_array(encoder, &sub, len);
+             if (err && !isOomError(err))
+                 return err;
+-            foreach (const QVariant &v2, list) {
++            for (const QVariant &v2 : t17::as_const(list)) {
+                 err = static_cast<CborError>(err | encodeVariant(&sub, v2));
+                 if (err && !isOomError(err))
+                     return err;
+-- 
+2.25.1
+

src/3rdparty/tinycbor/tests/encoder/tst_encoder.cpp

@@ -29,6 +29,19 @@
 #include <qfloat16.h>
 #endif
 
+#include <utility>
+namespace t17 {
+#ifdef __cpp_lib_as_const
+    using std::as_const;
+#else
+    template <typename T>
+    constexpr typename std::add_const<T>::type &as_const(T &t) noexcept { return t; }
+    // prevent rvalue arguments:
+    template <typename T>
+    void as_const(const T &&) = delete;
+#endif // __cpp_lib_as_const
+} // namespace t17
+
 Q_DECLARE_METATYPE(CborError)
 namespace QTest {
 template<> char *toString<CborError>(const CborError &err)
@@ -153,7 +166,7 @@ CborError encodeVariant(CborEncoder *encoder, const QVariant &v)
             CborError err = cbor_encoder_create_array(encoder, &sub, len);
             if (err && !isOomError(err))
                 return err;
-            foreach (const QVariant &v2, list) {
+            for (const QVariant &v2 : t17::as_const(list)) {
                 err = static_cast<CborError>(err | encodeVariant(&sub, v2));
                 if (err && !isOomError(err))
                     return err;