Doc: Remove wrong \obsolete doc comments

Change-Id: I541f12fab128493235716fb73d65f4ab0a62bb82
Reviewed-by: Lars Knoll <[email protected]>

src/corelib/text/qbytearray.cpp

@@ -1276,7 +1276,7 @@ QByteArray &QByteArray::operator=(const char *str)
 /*! \fn QByteArray::operator const char *() const
     \fn QByteArray::operator const void *() const
 
-    \obsolete Use constData() instead.
+    \note Use constData() instead in new code.
 
     Returns a pointer to the data stored in the byte array. The
     pointer can be used to access the bytes that compose the array.
@@ -2660,7 +2660,8 @@ bool QByteArray::isLower() const
     Returns a byte array that contains the first \a len bytes of this byte
     array.
 
-    \obsolete Use first() instead in new code.
+    If you know that \a len cannot be out of bounds, use first() instead in new
+    code, because it is faster.
 
     The entire byte array is returned if \a len is greater than
     size().
@@ -2682,7 +2683,8 @@ QByteArray QByteArray::left(qsizetype len)  const
 /*!
     Returns a byte array that contains the last \a len bytes of this byte array.
 
-    \obsolete Use last() instead in new code.
+    If you know that \a len cannot be out of bounds, use last() instead in new
+    code, because it is faster.
 
     The entire byte array is returned if \a len is greater than
     size().
@@ -2704,7 +2706,8 @@ QByteArray QByteArray::right(qsizetype len) const
     Returns a byte array containing \a len bytes from this byte array,
     starting at position \a pos.
 
-    \obsolete Use sliced() instead in new code.
+    If you know that \a pos and \a len cannot be out of bounds, use sliced()
+    instead in new code, because it is faster.
 
     If \a len is -1 (the default), or \a pos + \a len >= size(),
     returns a byte array containing all bytes starting at position \a

src/corelib/text/qstring.cpp

@@ -4613,7 +4613,8 @@ QString QString::section(const QRegularExpression &re, qsizetype start, qsizetyp
     Returns a substring that contains the \a n leftmost characters
     of the string.
 
-    \obsolete Use first() instead in new code.
+    If you know that \a n cannot be out of bounds, use first() instead in new
+    code, because it is faster.
 
     The entire string is returned if \a n is greater than or equal
     to size(), or less than zero.
@@ -4631,7 +4632,8 @@ QString QString::left(qsizetype n)  const
     Returns a substring that contains the \a n rightmost characters
     of the string.
 
-    \obsolete Use last() instead in new code.
+    If you know that \a n cannot be out of bounds, use last() instead in new
+    code, because it is faster.
 
     The entire string is returned if \a n is greater than or equal
     to size(), or less than zero.
@@ -4649,7 +4651,8 @@ QString QString::right(qsizetype n) const
     Returns a string that contains \a n characters of this string,
     starting at the specified \a position index.
 
-    \obsolete Use sliced() instead in new code.
+    If you know that \a position and \a n cannot be out of bounds, use sliced()
+    instead in new code, because it is faster.
 
     Returns a null string if the \a position index exceeds the
     length of the string. If there are less than \a n characters
@@ -9114,7 +9117,8 @@ QString &QString::setRawData(const QChar *unicode, qsizetype size)
     Returns the substring of length \a length starting at position
     \a start in this Latin-1 string.
 
-    \obsolete Use sliced() instead in new code.
+    If you know that \a start and \a length cannot be out of bounds, use sliced()
+    instead in new code, because it is faster.
 
     Returns an empty Latin-1 string if \a start exceeds the
     length of this Latin-1 string. If there are less than \a length characters
@@ -9129,7 +9133,8 @@ QString &QString::setRawData(const QChar *unicode, qsizetype size)
     \fn QLatin1String QLatin1String::left(qsizetype length) const
     \since 5.8
 
-    \obsolete Use first() instead in new code.
+    If you know that \a length cannot be out of bounds, use first() instead in
+    new code, because it is faster.
 
     Returns the substring of length \a length starting at position
     0 in this Latin-1 string.
@@ -9144,7 +9149,8 @@ QString &QString::setRawData(const QChar *unicode, qsizetype size)
     \fn QLatin1String QLatin1String::right(qsizetype length) const
     \since 5.8
 
-    \obsolete Use last() instead in new code.
+    If you know that \a length cannot be out of bounds, use last() instead in
+    new code, because it is faster.
 
     Returns the substring of length \a length starting at position
     size() - \a length in this Latin-1 string.