Sentinel while loop for C++
A “sentinel” in this context is a special value used to indicate the end of a sequence. The most common sentinel is \0 at the end of strings. A “sentinel while loop” would typically have the form:
C++
Is “argv[0] = name-of-executable” an accepted standard or just a common convention?
Guesswork (even educated guesswork) is fun but you really need to go to the standards documents to be sure. For example, ISO C11 states (my emphasis): If the value of argc is greater than zero, the string pointed to by argv[0] represents the program name; argv[0][0] shall be the null character if the program name is not available from the host environment. … Read more
How to pass optional arguments to a method in C++?
Here is an example of passing mode as optional parameter you can call myfunc in both ways and both are valid
Correct way to use cin.fail()
cin.fail() returns true if the last cin command failed, and false otherwise. An example: Now suppose you have a text file – input.txt and it’s contents are: When you will run above short program on that, it will result like: it will not continue after 6th value as it quits after reading the seventh word, because that … Read more
Does C++ have a Garbage Collector?
Native C++ by default has no such thing (the closest thing to this are the smart pointers, but that’s still something entirely different), but that doesn’t prevent you from writing your own garbage collection solution (or using third party solution). Managed C++ (and its successor C++/CLI) of course use .NET garbage collection for managed resources (though … Read more
C++ on mac : linker command failed with exit code 1 (use -v to see invocation)
You can only have one main() – you decide which one you need to keep and which one needs to be deleted. Keep only one page, with the main() method.
cin >> “no operator matches these operands”
I’ve been working on a C++ project in visual studio 2012 console mode and I keep getting this strange persistent error with the cin function. Under the >> I get a red line and the program tells me no operator matches these operands. I have initialized all the array elements in a separate method. Here’s a snippet example (The actual … Read more
basic_string::_M_construct null not valid after constructing subvector of strings
The chunk vector ceases to exist at the end of the for loop body. It’s still referenced by some thread. That’s called a dangling reference, and it’s not good. The error that you see may however be related to Result. Its definition isn’t provided (at the time of writing this answer) so it’s difficult to say. Remember that as the one … Read more
Sorting Characters Of A C++ String
There is a sorting algorithm in the standard library, in the header <algorithm>. It sorts inplace, so if you do the following, your original word will become sorted. If you don’t want to lose the original, make a copy first.
How does std::forward work? [duplicate]
First, let’s take a look at what std::forward does according to the standard: §20.2.3 [forward] p2 Returns: static_cast<T&&>(t) (Where T is the explicitly specified template parameter and t is the passed argument.) Now remember the reference collapsing rules: (Shamelessly stolen from this answer.) And then let’s take a look at a class that wants to employ perfect forwarding: And now an example invocation: … Read more