Support for variable length arrays (VLAs) was added to the C language in C99. It’s likely that since support for them exists in gcc (to support C99), it was relatively straightforward to add support for them to g++. That said, it’s an implementation-specific language extension, and it’s not a good idea to use implementation-specific extensions … Read more
Up through the C++20 standard, ostream::operator<< has the following overloads, among others: ostream& operator<< (bool val ); ostream& operator<< (const void* val ); When you pass in a volatile pointer, the second overload can’t apply because volatile pointers cannot be converted to non-volatile without an explicit cast. However, any pointer can be converted to bool, … Read more
According to the documentation: getFields() Returns an array containing Field objects reflecting all the accessible public fields of the class or interface represented by this Class object. The elements in the array returned are not sorted and are not in any particular order. This method returns an array of length 0 if the class or … Read more
I’m the founder of Coderbyte and also the guy who created this gets(stdin) hack. The comments on this post are correct that it is a form of find-and-replace, so let me explain why I did this really quickly. Back in the day when I first created the site (around 2012), it only supported JavaScript. There … Read more
Upon an object reaching the end of its lifetime, all pointers to it become indeterminate. This applies to block-scope variables and to malloced memory just the same. The applicable clause is, in C11, 6.2.4:2. The lifetime of an object is the portion of program execution during which storage is guaranteed to be reserved for it. … Read more
–> is not an operator. It is in fact two separate operators, — and >. The conditional’s code decrements x, while returning x‘s original (not decremented) value, and then compares the original value with 0 using the > operator. To better understand, the statement could be written as follows: while( (x–) > 0 )
Yes ([dcl.constexpr], ยง7.1.5/2 in the C++11 standard): “constexpr functions and constexpr constructors are implicitly inline (7.1.2).” Note, however, that the inline specifier really has very little (if any) effect upon whether a compiler is likely to expand a function inline or not. It does, however, affect the one definition rule, and from that perspective, the … Read more
In a character class (square brackets) any character except ^, -, ] or \ is a literal. This website is a brilliant reference and has lots of info on the nuances of different regex flavours. http://www.regular-expressions.info/refcharclass.html
According to this page (the 5.0 online manual), it’s for better performance and user convenience.
You are reading the sentence incorrectly. A program shall contain a global function called main, which is the designated start of the program. The standard is DEFINING the word “start” for the purposes of the remainder of the standard. It doesn’t say that no code executes before main is called. It says that the start … Read more