大约有 41,000 项符合查询结果（耗时：0.0199秒） [XML]
In what cases do I use malloc and/or new?
...
malloc is not typesafe in any meaningful way. In C++ you are required to cast the return from void*. This potentially introduces a lot of problems:
#include <stdlib.h>
struct foo {
double d[5];
};
int main() {
foo *f1 = malloc(1); // error, no cast
foo *f2 = static_cast<foo*>...
Deserialize JSON into C# dynamic object?
...string, object>
? new List<object>(arrayList.Cast<IDictionary<string, object>>().Select(x => new DynamicJsonObject(x)))
: new List<object>(arrayList.Cast<object>());
}
return result;
}
...
Convert char to int in C and C++
... code, you can write
char a = 'a';
int ia = (int)a;
/* note that the int cast is not necessary -- int ia = a would suffice */
to convert the character '0' -> 0, '1' -> 1, etc, you can write
char a = '4';
int ia = a - '0';
/* check here if ia is bounded by 0 and 9 */
Explanation:
a - '0'...
Printing hexadecimal characters in C
...
My solution using a cast to unsigned char is one instruction smaller in gcc4.6 for x86-64...
– lvella
Nov 9 '11 at 15:20
...
PHP json_encode encoding numbers as strings
...m might be there : I've often seen data come from database with everything casted to string (I've seen this with PDO and mssql ; but, if I remember correctly, this also happens for MySQL in PHP < 5.3, when the new mysqlnd driver was not yet existing) ;; to check what your data look like, you can ...
What is the proper way to check for null values?
... @BlackBear but the value returned is most probably a string, so the cast is valid
– Firo
Mar 20 '12 at 14:29
Th...
What's the strangest corner case you've seen in C# or .NET? [closed]
... All the methods are overridden, except GetType() which can't be; so it is cast (boxed) to object (and hence to null) to call object.GetType()... which calls on null ;-p
Update: the plot thickens... Ayende Rahien threw down a similar challenge on his blog, but with a where T : class, new():
priv...
Type erasure techniques
...ght type is returned
T*& operator[](size_t i) { return reinterpret_cast<T*&>(Vector<void*>::operator[](i)); }
};
As you can see, we have a strongly typed container but Vector<Animal*>, Vector<Dog*>, Vector<Cat*>, ..., will share the same (C++ and binary) c...
Why do we need virtual functions in C++?
...eclaration and calls in a main function etc. Pointer-to-derived implicitly casts to pointer-to-base (more specialized implicitly casts to more general). Visa-versa you need an explicit cast, usually a dynamic_cast. Anything else - very prone to undefined behavior so make sure you know what you're do...
How to convert xml into array in php?
...
if you cast to array, you dont need json_encode and json_decode.
– Ismael Miguel
Jan 28 '14 at 23:20
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