Add literal operators for QLatin1String and QLatin1Char

The operators are declared in the Qt::Literals::StringLiterals
namespace, to avoid collisions in the global namespace.

[ChangeLog][QtCore][QLatin1String] Added literal operator""_L1 that
converts string literals and chars to QLatin1String and QLatin1Char.

Fixes: QTBUG-98434
Change-Id: Ia945a6acf4b8d4fbbb5f803264e4d79d7b17a8da
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>

5 files changed, 95 insertions, 0 deletions

diff --git a/src/corelib/text/qchar.cpp b/src/corelib/text/qchar.cpp
index d4a30c1dc6..f9ada412c0 100644
--- a/src/corelib/text/qchar.cpp
+++ b/src/corelib/text/qchar.cpp
@@ -1821,6 +1821,23 @@ QDataStream &operator>>(QDataStream &in, QChar &chr)
     that of \a c2; otherwise returns \c false.
 */
 
+/*!
+    \fn Qt::Literals::StringLiterals::operator""_L1(char ch)
+
+    \relates QLatin1Char
+    \since 6.4
+
+    Literal operator that creates a QLatin1Char out of \a ch.
+
+    The following code creates a QLatin1Char:
+    \code
+    using namespace Qt::Literals::StringLiterals;
+
+    auto ch = 'a'_L1;
+    \endcode
+
+    \sa Qt::Literals::StringLiterals
+*/
 
 // ---------------------------------------------------------------------------
 
diff --git a/src/corelib/text/qchar.h b/src/corelib/text/qchar.h
index f8d63c54f1..c391dd13ec 100644
--- a/src/corelib/text/qchar.h
+++ b/src/corelib/text/qchar.h
@@ -654,6 +654,19 @@ Q_CORE_EXPORT QDataStream &operator<<(QDataStream &, QChar);
 Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QChar &);
 #endif
 
+namespace Qt {
+inline namespace Literals {
+inline namespace StringLiterals {
+
+constexpr inline QLatin1Char operator"" _L1(char ch) noexcept
+{
+    return QLatin1Char(ch);
+}
+
+} // StringLiterals
+} // Literals
+} // Qt
+
 QT_END_NAMESPACE
 
 namespace std {
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index ae5f57ce41..9b6fe88cf1 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -10850,6 +10850,25 @@ QString QString::toHtmlEscaped() const
 */
 
 /*!
+    \fn Qt::Literals::StringLiterals::operator""_L1(const char *str, size_t size)
+
+    \relates QLatin1String
+    \since 6.4
+
+    Literal operator that creates a QLatin1String out of the first \a size
+    characters in the char string literal \a str.
+
+    The following code creates a QLatin1String:
+    \code
+    using namespace Qt::Literals::StringLiterals;
+
+    auto str = "hello"_L1;
+    \endcode
+
+    \sa Qt::Literals::StringLiterals
+*/
+
+/*!
     \internal
  */
 void QAbstractConcatenable::appendLatin1To(QLatin1String in, QChar *out) noexcept
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 350659ed46..c8c25da3cc 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -1589,6 +1589,19 @@ inline QString operator"" _qs(const char16_t *str, size_t size) noexcept
 }
 } // QtLiterals
 
+namespace Qt {
+inline namespace Literals {
+inline namespace StringLiterals {
+
+constexpr inline QLatin1String operator"" _L1(const char *str, size_t size) noexcept
+{
+    return QLatin1String(str, qsizetype(size));
+}
+
+} // StringLiterals
+} // Literals
+} // Qt
+
 QT_END_NAMESPACE
 
 #if defined(QT_USE_FAST_OPERATOR_PLUS) || defined(QT_USE_QSTRINGBUILDER)
diff --git a/src/corelib/text/qtliterals.qdoc b/src/corelib/text/qtliterals.qdoc
index d5875c3e08..ce248ab5ed 100644
--- a/src/corelib/text/qtliterals.qdoc
+++ b/src/corelib/text/qtliterals.qdoc
@@ -31,3 +31,36 @@
 
     \brief The QtLiterals namespace declares literal operators for Qt types.
 */
+
+/*!
+    \namespace Qt::Literals
+    \inmodule QtCore
+
+    \brief The Literals inline namespace declares literal operators for Qt types.
+*/
+
+/*!
+    \namespace Qt::Literals::StringLiterals
+    \inmodule QtCore
+
+    \brief The StringLiterals namespace declares string literal operators
+    for Qt types.
+
+    The inline Qt::Literals::StringLiterals namespace declares string literal
+    operators for Qt types. Because both \c Literals and \c StringLiterals
+    namespaces are declared as inline, the symbols from this namespace can be
+    accessed by adding one of the following to your code:
+
+    \code
+    // Makes visible only the literal operators declared in StringLiterals
+    using namespace Qt::Literals::StringLiterals;
+
+    // Makes visible literal operators declared in all inline namespaces
+    // inside Literals
+    using namespace Qt::Literals;
+
+    // Makes visible all symbols (including all literal operators) declared
+    // in the Qt namespace
+    using namespace Qt;
+    \endcode
+*/