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When is a C++ destructor called?
...arge enough to hold 5 Foo objects.
int n = 5;
char *chunk = static_cast<char*>(::operator new(sizeof(Foo) * n));
// Use placement new to construct Foo instances at the right places in the chunk.
for(int i=0; i<n; ++i)
{
new (chunk + i*sizeof(Foo)) Foo(i);
}
...
How do I check if a type is a subtype OR the type of an object?
...lue);
if (testInstance==null)
throw new InvalidCastException("HelperType must be derived from A");
_helperType = value;
}
}
}
I feel like I might be a bit naive here so any feedback would be welcome.
...
C++ preprocessor __VA_ARGS__ number of arguments
...
@Adam Because I cast {__VA_ARGS__} to int[], it is just int[], regardless of actual content of __VA_ARGS__
– qrdl
Jan 23 '10 at 20:45
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When should I use double instead of decimal?
...ecimal is causing bottlenecks or slow-downs. In those cases, I will "down cast" to double or float, but only do it internally, and carefully try to manage precision loss by limiting the number of significant digits in the mathematical operation being performed.
In general, if your value is transie...
What is array to pointer decay?
...
const int a[] = { 2, 3, 5, 7, 11 };
into a pointer (which works without casting, and therefore can happen unexpectedly in some cases):
const int* p = a;
you lose the ability of the sizeof operator to count elements in the array:
assert( sizeof(p) != sizeof(a) ); // sizes are not equal
This...
Java Interfaces/Implementation naming convention [duplicate]
...Truck.
When you are using the Interface in place of a sub-class you just cast it to Truck. As in List<Truck>. Putting I in front is just Hungarian style notation tautology that adds nothing but more stuff to type to your code.
All modern Java IDE's mark Interfaces and Implementations and ...
How can I ensure that a division of integers is always rounded up?
...ounded up if necessary. Is there a better way than this? There is a lot of casting going on. :-)
8 Answers
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Why do std::shared_ptr work
...late <typename T>
void delete_deleter( void * p ) {
delete static_cast<T*>(p);
}
template <typename T>
class my_unique_ptr {
std::function< void (void*) > deleter;
T * p;
template <typename U>
my_unique_ptr( U * p, std::function< void(void*) > deleter ...
How to check if an object is a certain type
... type for the TypeName Bar.
In some instances, the type an object has been Cast to is different from the type an object was first instantiated from. In the following example, MyObj is an Integer cast into an Object:
Dim MyVal As Integer = 42
Dim MyObj As Object = CType(MyVal, Object)
So, is MyObj...
How do I reflect over the members of dynamic object?
...lt;string, object> for its properties, so the solution is as trivial as casting:
IDictionary<string, object> propertyValues = (IDictionary<string, object>)s;
Note that this will not work for general dynamic objects. In these cases you will need to drop down to the DLR via IDynamic...