I create a simple array of 100 equal values of 0.1 floats and sum them up using the following straightforward code:
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#include <array> #include <numeric> #include <iostream> int main() { std::array<float, 100> a; std::fill(a.begin(), a.end(), 0.1f); std::cout << std::accumulate(a.begin(), a.end(), 0) << std::endl; return 0; } |
The expected result is 10. Why this simple program prints the result 0 ?
The metafactor C++ library was primarily developed for compile-time factorization of integers up to 32-bit unsigned maximum. As a side-effect, using the algorithms of this library, I could generate big list of primes at compile-time. It turns out that a list of primes less than 65536 (16-bit unsigned integers) can be generated by Clang 3.8 C++ compiler within 5 minutes of compilation time. Apparently, such a list is enough to check any 32-bit unsigned integer for primality or can be used for other purposes. Continue reading