How performing multiple matrix multiplications in CUDA?

I think it’s likely that the fastest performance will be achieved by using the CUBLAS batch gemm function which was specifically designed for this purpose (performing a large number of “relatively small” matrix-matrix multiply operations). Even though you want to multiply your array of matrices (M[]) by a single matrix (N), the batch gemm function … Read more

Why Doesn’t reinterpret_cast Force copy_n for Casts between Same-Sized Types?

why doesn’t reinterpret_cast handle that for me? One reason is that the size, alignment, and bit representations aren’t specified, so such a conversion wouldn’t be portable. However, that wouldn’t really justify making the behaviour undefined, just implementation-defined. By making it undefined, the compiler is allowed to assume that expressions of unrelated types don’t access the … Read more

cin >> fails with bigger numbers but works with smaller ones?

Try: std::cout << std::numeric_limits<int>::max() << std::endl; // requires you to #include <limits> int on your system is likely a 32-bit signed two’s complement number, which means the max value it can represent is 2,147,483,647. Your number, 3,999,999,999, is larger than that, and can’t be properly represented by int. cin fails, alerting you of the problem. … Read more

Most terse and reusable way of wrapping template or overloaded functions in function objects

You can create a macro like #define FUNCTORIZE(func) [](auto&&… val) \ noexcept(noexcept(func(std::forward<decltype(val)>(val)…))) -> decltype(auto) \ {return func(std::forward<decltype(val)>(val)…);} which will let you wrap any callable into a closure object. You would use it like auto constexpr predObj = FUNCTORIZE(pred);

Why statements cannot appear at namespace scope?

The expression p++ which you’ve written is at namespace scope. It is forbidden by the grammer of namespace-body which is defined in §7.3.1/1 as: namespace-body:      declaration-seqopt which says the namespace-body can optionally contain only declaration. And p++ is surely not a declaration, it is an expression, therefore the Standard implicitly forbids it. The Standard might … Read more