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What is the difference between char s[] and char *s?
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static char __unnamed[] = "abc";
char *c = __unnamed;
Note the implicit cast from char[] to char *, which is always legal.
Then if you modify c[0], you also modify __unnamed, which is UB.
This is documented at 6.4.5 "String literals":
5 In translation phase 7, a byte or code of value zero i...
Why is the default value of the string type null instead of an empty string?
..., and (2) an unfortunate extra layer of boxing indirection any time it was cast to Object. Given that the heap representation of string is unique, having special treatment to avoid extra boxing wouldn't have been much of a stretch (actually, being able to specify non-default boxing behaviors would ...
What exactly do “IB” and “UB” mean?
...by the compiler writers. An example of this is the result of a reinterpret_cast. usually, it simply changes the type of a pointer, without modifying the address, but the mapping is actually implementation-defined, so a compiler could map to a completely different address, as long as it documented th...
What is a NullReferenceException, and how do I fix it?
...design philosophy, would at least resolve the NullReferenceException here.
Cast with as
var myThing = someObject as Thing;
This doesn't throw an InvalidCastException but returns a null when the cast fails (and when someObject is itself null). So be aware of that.
LINQ FirstOrDefault() and SingleOrD...
How to implement an STL-style iterator and avoid common pitfalls?
... size))
{
std::cout << " char: " << static_cast<char>(n) << std::endl;
}
}
{
// Only for iterator test
ptr_iterator<uint8_t> first(data);
ptr_iterator<uint8_t> last(first + size);
std::vector<u...
What is the difference between an int and an Integer in Java and C#?
... you can access methods on the heap object directly, but in C# you need to cast it back to an int, which will create another copy. Thus, the object on the heap cannot easily be changed in C# without creating a new boxed copy of a new int value. (Ugh, this paragraph doesn't read all that easily.)
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Why does an overridden function in the derived class hide other overloads of the base class?
... interface. So maybe d->foo() won't get you the "Is-a Base", but static_cast<Base*>(d)->foo() will, including dynamic dispatch.
– Kerrek SB
Jan 9 '14 at 13:36
12
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How and where are Annotations used in Java?
...s:
Class instance creation expression:
new @Interned MyObject();
Type cast:
myString = (@NonNull String) str;
implements clause:
class UnmodifiableList implements
@Readonly List<@Readonly T> { ... }
Thrown exception declaration:
void monitorTemperature() throws
@C...
What is a serialVersionUID and why should I use it?
... read
Unnecessary code: Redundant null check
Unnecessary code: Unnecessary cast or 'instanceof'
and many more.
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How to implement a custom AlertDialog View
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This gives a ClassCastException when the custom layout contains an EditText, because getCurrentFocus() will return the EditText and an EditText can't be cast to a ViewGroup. Using null as the second argument fixes this.
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