diff options
Diffstat (limited to 'src/corelib/tools/qstringview.cpp')
| -rw-r--r-- | src/corelib/tools/qstringview.cpp | 56 |
1 files changed, 40 insertions, 16 deletions
diff --git a/src/corelib/tools/qstringview.cpp b/src/corelib/tools/qstringview.cpp index ce8fdacafb..c863ca7ce2 100644 --- a/src/corelib/tools/qstringview.cpp +++ b/src/corelib/tools/qstringview.cpp @@ -38,6 +38,7 @@ ****************************************************************************/ #include "qstringview.h" +#include "qstring.h" QT_BEGIN_NAMESPACE @@ -74,19 +75,14 @@ QT_BEGIN_NAMESPACE string literal. QStringViews should be passed by value, not by reference-to-const: - \code - void myfun1(QStringView sv); // preferred - void myfun2(const QStringView &sv); // compiles and works, but slower - \endcode + \snippet code/src_corelib_tools_qstringview.cpp 0 If you want to give your users maximum freedom in what strings they can pass to your function, accompany the QStringView overload with overloads for \list \li \e QChar: this overload can delegate to the QStringView version: - \code - void fun(QChar ch) { fun(QStringView(&ch, 1)); } - \endcode + \snippet code/src_corelib_tools_qstringview.cpp 1 even though, for technical reasons, QStringView cannot provide a QChar constructor by itself. \li \e QString: if you store an unmodified copy of the string and thus would @@ -237,9 +233,9 @@ QT_BEGIN_NAMESPACE The range \c{[str,len)} must remain valid for the lifetime of this string view object. - Passing \c nullptr as \a str is safe if \a len is 0, too, and results in a null string view. + Passing \nullptr as \a str is safe if \a len is 0, too, and results in a null string view. - The behavior is undefined if \a len is negative or, when positive, if \a str is \c nullptr. + The behavior is undefined if \a len is negative or, when positive, if \a str is \nullptr. This constructor only participates in overload resolution if \c Char is a compatible character type. The compatible character types are: \c QChar, \c ushort, \c char16_t and @@ -254,11 +250,11 @@ QT_BEGIN_NAMESPACE The range \c{[first,last)} must remain valid for the lifetime of this string view object. - Passing \c nullptr as \a first is safe if \a last is nullptr, too, + Passing \c \nullptr as \a first is safe if \a last is \nullptr, too, and results in a null string view. The behavior is undefined if \a last precedes \a first, or \a first - is \c nullptr and \a last is not. + is \nullptr and \a last is not. This constructor only participates in overload resolution if \c Char is a compatible character type. The compatible character types @@ -274,7 +270,7 @@ QT_BEGIN_NAMESPACE \a str must remain valid for the lifetime of this string view object. - Passing \c nullptr as \a str is safe and results in a null string view. + Passing \nullptr as \a str is safe and results in a null string view. This constructor only participates in overload resolution if \a str is not an array and if \c Char is a compatible character @@ -291,9 +287,7 @@ QT_BEGIN_NAMESPACE If you need the full array, use the constructor from pointer and size instead: - \code - auto sv = QStringView(array, std::size(array)); // using C++17 std::size() - \endcode + \snippet code/src_corelib_tools_qstringview.cpp 2 \a string must remain valid for the lifetime of this string view object. @@ -339,7 +333,7 @@ QT_BEGIN_NAMESPACE The string view will be empty if and only if \c{str.empty()}. It is unspecified whether this constructor can result in a null string view (\c{str.data()} would - have to return \c nullptr for this). + have to return \nullptr for this). \sa isNull(), isEmpty() */ @@ -801,4 +795,34 @@ QT_BEGIN_NAMESPACE \sa QString::isRightToLeft() */ +/*! + \since 5.14 + + Transcribes this string into the given \a array. + + Caller is responsible for ensuring \a array is large enough to hold the \t + wchar_t encoding of this string (allocating the array with the same length + as the string is always sufficient). The array is encoded in UTF-16 on + platforms where \t wchar_t is 2 bytes wide (e.g. Windows); otherwise (Unix + systems), \t wchar_t is assumed to be 4 bytes wide and the data is written + in UCS-4. + + \note This function writes no null terminator to the end of \a array. + + Returns the number of \t wchar_t entries written to \a array. + + \sa QString::toWCharArray() +*/ + +int QStringView::toWCharArray(wchar_t *array) const +{ + if (sizeof(wchar_t) == sizeof(QChar)) { + memcpy(array, data(), sizeof(QChar) * size()); + return size(); + } else { + return QString::toUcs4_helper(reinterpret_cast<const ushort *>(data()), int(size()), + reinterpret_cast<uint *>(array)); + } +} + QT_END_NAMESPACE |