QChar: make construction from integral explicit

QChar should not be convertible from any integral type except from
char16_t, short and possibly char (since it's a direct superset).

David provided the perfect example:

  if (str == 123) { ~~~ }

compiles, with 123 implicitly converted to QChar (str == "123"
was meant instead). But similarly one can construct other
scenarios where QString(123) gets accidentally used (instead of
QString::number(123)), like QString s; s += 123;.

Add a macro to revert to the implicit constructors, for backwards
compatibility.

The breaks are mostly in tests that "abuse" of integers (arithmetic,
etc.). Maybe it's time for user-defined literals for QChar/QString,
but that is left for another commit.

[ChangeLog][Potentially Source-Incompatible Changes][QChar] QChar
constructors from integral types are now by default explicit.
It is recommended to use explicit conversions, QLatin1Char,
QChar::fromUcs4 instead of implicit conversions. The old behavior
can be restored by defining the QT_IMPLICIT_QCHAR_CONSTRUCTION
macro.

Change-Id: I6175f6ab9bcf1956f6f97ab0c9d9d5aaf777296d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 30 insertions, 30 deletions

diff --git a/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp b/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp
index c3ad151a51..a457744867 100644
--- a/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp
+++ b/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp
@@ -610,7 +610,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.1") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.1-1") << utf8 << str << -1;
 
     // 3.3.2
@@ -620,7 +620,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.2-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -628,7 +628,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.2-2") << utf8 << str << -1;
     utf8 += 0x30;
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.2-3") << utf8 << str << -1;
 
     // 3.3.3
@@ -639,7 +639,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.3") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.3-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -647,7 +647,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.3-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.3-3") << utf8 << str << -1;
 
     utf8.clear();
@@ -656,7 +656,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.3-4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.3-5") << utf8 << str << -1;
 
     // 3.3.4
@@ -668,7 +668,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -678,7 +678,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-3") << utf8 << str << -1;
 
     utf8.clear();
@@ -687,7 +687,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-5") << utf8 << str << -1;
 
     utf8.clear();
@@ -695,7 +695,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-6") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.4-7") << utf8 << str << -1;
 
     // 3.3.5
@@ -708,7 +708,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -719,7 +719,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-3") << utf8 << str << -1;
 
     utf8.clear();
@@ -729,7 +729,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-5") << utf8 << str << -1;
 
     utf8.clear();
@@ -738,7 +738,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-6") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-7") << utf8 << str << -1;
 
     utf8.clear();
@@ -746,7 +746,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-8") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.5-9") << utf8 << str << -1;
 
     // 3.3.6
@@ -755,7 +755,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.6") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.6-1") << utf8 << str << -1;
 
     // 3.3.7
@@ -765,7 +765,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.7") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.7-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -773,7 +773,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.7-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.7-3") << utf8 << str << -1;
 
     // 3.3.8
@@ -784,7 +784,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.8") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.8-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -793,7 +793,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.8-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.8-3") << utf8 << str << -1;
 
     utf8.clear();
@@ -801,7 +801,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.8-4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.8-5") << utf8 << str << -1;
 
     // 3.3.9
@@ -813,7 +813,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -823,7 +823,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-3") << utf8 << str << -1;
 
     utf8.clear();
@@ -832,7 +832,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-5") << utf8 << str << -1;
 
     utf8.clear();
@@ -840,7 +840,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-6") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.9-7") << utf8 << str << -1;
 
     // 3.3.10
@@ -853,7 +853,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-1") << utf8 << str << -1;
 
     utf8.clear();
@@ -864,7 +864,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-2") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-3") << utf8 << str << -1;
 
     utf8.clear();
@@ -874,7 +874,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-4") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-5") << utf8 << str << -1;
 
     utf8.clear();
@@ -883,7 +883,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-6") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-7") << utf8 << str << -1;
 
     utf8.clear();
@@ -891,7 +891,7 @@ void tst_QStringConverter::utf8Codec_data()
     str = fromInvalidUtf8Sequence(utf8);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-8") << utf8 << str << -1;
     utf8 += char(0x30);
-    str += 0x30;
+    str += QChar(0x30);
     QTest::newRow("http://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html 3.3.10-9") << utf8 << str << -1;
 
     // 3.4