When you call placement new on a buffer: A *a = new (buf) A; you are invoking the built-in void* operator new (std::size_t size, void* ptr) noexcept as defined in: c++11 18.6.1.3 Placement forms [new.delete.placement] These functions are reserved, a C++ program may not define functions that displace the versions in the Standard C++ library … Read more
The problem you’re having is that the compiler doesn’t know which versions of your template to instantiate. When you move the implementation of your function to x.cpp it is in a different translation unit from main.cpp, and main.cpp can’t link to a particular instantiation because it doesn’t exist in that context. This is a well-known … Read more
I’m surprised at all the answers suggesting vector. They aren’t even the same thing! Use std::fill, from <algorithm>: int directory[100]; std::fill(directory, directory + 100, -1); Not concerned with the question directly, but you might want a nice helper function when it comes to arrays: template <typename T, size_t N> T* end(T (&pX)[N]) { return pX … Read more
Default template arguments are not part of the signature of a template (so both definitions try to define the same template twice). Their parameter types are part of the signature, however. So you can do template <class T> class check { public: template< class U = T, typename std::enable_if<std::is_same<U, int>::value, int>::type = 0> inline static … Read more
Confirmed that it doesn’t work here as well. (Recent GCC 4.6 snapshot). You could do the obvious and simply define it before you include any std:: headers. A bit dirty but will work until GCC fixes it (unless this is intended behavior). The #define shouldn’t break anything anyways. Either in source or -D_GLIBCXX_USE_NANOSLEEP flag to … Read more
The files are being removed because make considers them “intermediate”. When make forms a chain of rules to produce a prerequisite, it treats all files created by the intermediate chains as “intermediate” and removes then when the target is created. See Chained Rules in the manual for GNU make. In your case, you can prevent … Read more
you may want to specify the C++ version with g++ -std=c++11 tmp.cpp -o tmp I don’t have gcc 4.8.1 at hand , but in older versions of GCC, you can use g++ -std=c++0x tmp.cpp -o tmp At least gcc 4.9.2 I believe also support part of C++14 by specifying g++ -std=c++1y tmp.cpp -o tmp Update: … Read more
The reason is because they’re initialized in the order they’re declared in your class, not the order you initialize them in the constructor and it’s warning you that your constructor’s order won’t be used. This is to help prevent errors where the initialization of b depends on a or vice-versa. The reason for this ordering … Read more
A .gch file is a precompiled header. If a .gch is not found then the normal header files will be used. However, if your project is set to generate pre-compiled headers it will make them if they don’t exist and use them in the next build. Sometimes the *.h.gch will get corrupted or contain outdated … Read more
Update 2 This question was merged with an exact duplicate, on taking a look at this, the actual answer is much simpler than anyone originally thought. The current version of std_lib_facilities.h includes the following line: inline double sqrt(int x) { return sqrt(double(x)); } // to match C++0x which creates a specific overload for the int … Read more