Question

我希望将我的班级转换为双倍值。这可以通过重载double y = x来实现，但这允许隐式转换，理想情况下我希望能够避免。

是否有任何方法可以添加此功能，但要求使用employee_array = [[1, 10, 9] [2, 19, 4] [3, 7, 6]] employees = [Employee(*row) for row in employee_array]进行转换，而不是隐式进行转换; xmlns:fcu="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,5)" ... <Button fcu:Style="{StaticResource ButtonRevealStyle}" Grid.Column="1" Width="38" ... />？

我正在使用C ++ 17。感谢

Answer 1

是的，您可以在C ++ 11之后将转换运算符标记为显式。

try

这将阻止复制初始化，例如，

final String propertyUsedForSorting = "firstName";
Arrays.sort(persons, new Comparator<Person>() {
    @Override
    public int compare(Person o1, Person o2) {
        try {
            Comparable prop1 = (Comparable) PropertyUtils.getProperty(o1, propertyUsedForSorting);
            Comparable prop2 = (Comparable) PropertyUtils.getProperty(o2, propertyUsedForSorting);
            return prop1.compareTo(prop2);
        } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
            throw new RuntimeException("Could not resolve the property: " + propertyUsedForSorting, e);
        } catch (ClassCastException e) {
            throw new RuntimeException("Cannot use property " + propertyUsedForSorting + " for sorting.");
        }
    }
});

允许显式转换，例如

explicit operator double() { /* ... */ }

Answer 2

使用double y(x); double y = static_cast<double>(x);：

sudo apt clean && sudo apt update

要求通过static_cast <double>（x）显式调用operator double（）

2 个答案: