From 12b41c3332612eb26b7b8598c0a94a4f0d709787 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Mon, 21 Oct 2024 14:56:01 +0200
Subject: QDebug: add streaming operators for std::tuple

Unlike the existing one for std::pair, make the operator SCARY, using
the newly-added StreamTypeErased type-erasure (added in
5cdd1f594d26e1d4f84b00741be1ab7231458512).

[ChangeLog][QtCore][QDebug] Can now stream std::tuple.

Change-Id: I46670ac32eaee7f0ea5f4543ebcf59e19b394166
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
---
 src/corelib/io/qdebug.cpp | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

(limited to 'src/corelib/io/qdebug.cpp')

diff --git a/src/corelib/io/qdebug.cpp b/src/corelib/io/qdebug.cpp
index 598355e4296..39eccd889cf 100644
--- a/src/corelib/io/qdebug.cpp
+++ b/src/corelib/io/qdebug.cpp
@@ -1086,6 +1086,33 @@ QByteArray QDebug::toBytesImpl(StreamTypeErased s, const void *obj)
     return result;
 }
 
+/*!
+    \internal
+    \since 6.9
+
+    Outputs a heterogeneous product type (pair, tuple, or anything that
+    implements the Tuple Protocol). The class name is described by "\a ns
+    \c{::} \a what", while the addresses of the \a n elements are stored in the
+    array \a data. The formatters are stored in the array \a ops.
+
+    If \a ns is empty, only \a what is used.
+*/
+QDebug &QDebug::putTupleLikeImplImpl(const char *ns, const char *what,
+                                     size_t n, StreamTypeErased *ops, const void **data)
+{
+    const QDebugStateSaver saver(*this);
+    nospace();
+    if (ns && *ns)
+        *this << ns << "::";
+    *this << what << '(';
+    while (n--) {
+        (*ops++)(*this, *data++);
+        if (n)
+            *this << ", ";
+    }
+    return *this << ')';
+}
+
 /*!
     \fn template <class T> QDebug operator<<(QDebug debug, const QList<T> &list)
     \relates QDebug
@@ -1179,6 +1206,14 @@ QByteArray QDebug::toBytesImpl(StreamTypeErased s, const void *obj)
     \c T need to support streaming into QDebug.
 */
 
+/*!
+    \fn template <class...Ts, QDebug::if_streamable<Ts...>> QDebug &QDebug::operator<<(const std::tuple<Ts...> &tuple)
+    \since 6.9
+
+    Writes the contents of \a tuple to the stream. All \c Ts... need to support
+    streaming into QDebug.
+*/
+
 /*!
     \fn template <class T1, class T2> QDebug operator<<(QDebug debug, const std::pair<T1, T2> &pair)
     \relates QDebug
-- 
cgit v1.2.3