On 04/05/2023 15:51, Sune Vuorela wrote:
On 2023-05-04, Marc Mutz via Development<development@qt-project.org> wrote:
that keeps unported code running. The main issue isn't the scoping, the
main issue will be the missing implicit conversion to underlying_type.
In few cases the implicit conversion to underlying_type is kind of important.
Especially in the cases where the api has int and is mostly used with
enums or is somehow user extendable.
Qt::ItemDataRole is one of them that comes to mind.
switch(role) {
case Qt::UserRole+1:
....
First of all, the use of Qt::UserRole+1 isn't really good practice.
Define your roles in a scoped enum. For this use case, we have been
using this little trick:
// Tool to convert class enum value to underlying type for easier use
template <typename E>
constexpr typename std::underlying_type<E>::type operator+(const E &e)
{
return static_cast<typename std::underlying_type<E>::type>(e);
}
Now, we can write the switch like this:
switch (role) {
case +Roles::Name: //...
case +Roles::Age: //...
Of course, you can also do:
switch (static_cast<Roles>(int)) {
case Roles::Name: //...
case Roles::Age: //...
But AFAIK, now you need to make sure the int value actually is in the
enum first to make that safe.
Cheers,
André
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