QStringEncoder/Decoder: add missing noexcept

The interesting part is what cannot be noexcept:

- nameForEncoding() and ctor from Encoding: because they don't handle
  all valid values of type Encoding, so have a narrow contract

- encodingForHtml(): because it allocates memory (→ QTBUG-101046)

Change-Id: I30cdc19a32537be047e43955e3337e4d6ccc363f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 4 insertions, 3 deletions

diff --git a/src/corelib/text/qstringconverter.cpp b/src/corelib/text/qstringconverter.cpp
index 199e85aaae..84569fccdd 100644
--- a/src/corelib/text/qstringconverter.cpp
+++ b/src/corelib/text/qstringconverter.cpp
@@ -1699,7 +1699,7 @@ static bool nameMatch(const char *a, const char *b)
 /*!
     \internal
 */
-QStringConverter::QStringConverter(const char *name, Flags f)
+QStringConverter::QStringConverter(const char *name, Flags f) noexcept
     : iface(nullptr), state(f)
 {
     auto e = encodingForName(name);
@@ -1745,7 +1745,7 @@ QStringConverter::QStringConverter(const char *name, Flags f)
     Returns an optional encoding for \a name. The optional is empty if the name could
     not get converted to a valid encoding.
 */
-std::optional<QStringConverter::Encoding> QStringConverter::encodingForName(const char *name)
+std::optional<QStringConverter::Encoding> QStringConverter::encodingForName(const char *name) noexcept
 {
     for (int i = 0; i < LastEncoding + 1; ++i) {
         if (nameMatch(encodingInterfaces[i].name, name))
@@ -1763,7 +1763,8 @@ std::optional<QStringConverter::Encoding> QStringConverter::encodingForName(cons
 
    The returned optional is empty, if the encoding is unclear.
  */
-std::optional<QStringConverter::Encoding> QStringConverter::encodingForData(QByteArrayView data, char16_t expectedFirstCharacter)
+std::optional<QStringConverter::Encoding>
+QStringConverter::encodingForData(QByteArrayView data, char16_t expectedFirstCharacter) noexcept
 {
     // someone set us up the BOM?
     qsizetype arraySize = data.size();