To make use of the range-based for-loop you have to provide either begin() and end() member functions or overload the non-member begin() and end() functions. In the latter case, you can wrap your range in a std::pair and overload begin() and end() for those: namespace std { template <typename T> T* begin(std::pair<T*, T*> const& p) … Read more
I can think of one scenario where it might be helpful to the compiler from an optimisation perspective. I’m not sure if it’s worth the effort to compiler implementers, but it’s theoretically possible at least. With virtual call dispatch on a derived, final type you can be sure that there is nothing else deriving from … Read more
I won’t say it is the “best way”, but a way is to use std::string‘s iterator constructor: std::array<char, 10> arr; … // fill in arr std::string str(std::begin(arr), std::end(arr));
Opinion plays a role here. The problem is that std::exception does not have a constructor that takes a string argument; this is an MSVC extension. I see two ways to go about it: Don’t pass a string argument Don’t use std::exception The first case is straightforward; just use throw std::exception(); The drawback is that you … Read more
In short, no, we can’t consider this a new language. It’s the same language, new features. But instead of being bolted on by using the Boost libs, they’re now going to be standard inclusions if you’re using a compiler that supports the 0x standard. One doesn’t have to use the new standard while using a … Read more
Don’t use %. This is a problem that calls for bitmasks: bool same_parity = (i & 0x1) == (j & 0x1); This works regardless of the sign of i, since the result of that expression will always be 0 or 1.
Why does libstdc++ use … … in it’s implementation of is_function? If we check out the cppreference section for std::is_function it gives a sample implementation and says for the first … … case: // specialization for variadic functions such as std::printf template<class Ret, class… Args> struct is_function<Ret(Args……)> : std::true_type {}; so we need the second … Read more
A bug report has been filed with the GCC team, and one of the developers has confirmed the issue on trunk. In the mean time, as LucDanton pointed out in chat, declaring the function static will solve the problem.
These two defect reports address your issue: Defect Report #316 Defect Report #317 Defect report 316 says (emphasis mine going forward): The rules for compatibility of function types in 6.7.5.3#15 do not define when a function type is “specified by a function definition that contains a (possibly empty) identifier list”, […] and it has a … Read more
Because when there is a template parameter involved, decltype returns an unqiue dependent type according to the standard, see below. If there is no template parameter then it resolves to an obvious size_t. So in this case you have to choose either both declaration and definition have an independent expression (e.g. size_t/decltype(sizeof(int))), as a return … Read more