No; you shouldn’t cast the result, since: It is unnecessary, as void * is automatically and safely promoted to any other pointer type in this case. It adds clutter to the code, casts are not very easy to read (especially if the pointer type is long). It makes you repeat yourself, which is generally bad. … Read more
Try this Object obj = ois.readObject(); // Check it’s an ArrayList if (obj instanceof ArrayList<?>) { // Get the List. ArrayList<?> al = (ArrayList<?>) obj; if (al.size() > 0) { // Iterate. for (int i = 0; i < al.size(); i++) { // Still not enough for a type. Object o = al.get(i); if (o … Read more
From Go’s FAQ, The standard library’s purpose is to support the runtime, connect to the operating system, and provide key functionality that many Go programs require, such as formatted I/O and networking. It also contains elements important for web programming, including cryptography and support for standards like HTTP, JSON, and XML. There is no clear … Read more
See PEP 357: Allowing Any Object to be Used for Slicing. The nb_int method is used for coercion and so means something fundamentally different than what is requested here. This PEP proposes a method for something that can already be thought of as an integer communicate that information to Python when it needs an integer. … Read more
It won’t blow up… but that doesn’t necessarily mean it’s safe. Typically when I use a cast for a reference conversion, it’s because I really, really think that the execution-time type is the one I’m specifying. If it’s not, that indicates a bug in my code – and I’d rather that manifested itself as an … Read more
float (*somethingAsMatrix)[2] = (float (*)[2]) matrixReturnAsArray;
According to the documentation (Explicit conversions) you can cast from a base type to a derived type. Since null is a valid value for all reference types, as long as the cast route exists you should be fine. object null → TestClass null works as object is a superclass to all reference types. However, if … Read more
Because the number can be up to 15 digits, you’ll need to cast to an 64 bit (8-byte) integer. Try this: SELECT * FROM table WHERE myint = mytext::int8 The :: cast operator is historical but convenient. Postgres also conforms to the SQL standard syntax myint = cast ( mytext as int8) If you have … Read more
No need to cast from or to a pointer to void in C: 6.3.2.3 Pointers 1 A pointer to void may be converted to or from a pointer to any incomplete or object type. A pointer to any incomplete or object type may be converted to a pointer to void and back again; the result … Read more