unsigned-long-long-int

The Standard Library class template std::bitset<N> has a constructor (C++11 and onwards, unsigned long argument before C++11) constexpr bitset(unsigned long long) noexcept Contrary to many best-practice guidelines, this single-argument constructor is not marked as explicit . What is the rationale behind this? TemplateRex Explicit construction The main objection against an explicit constructor is that copy-initialization from unsigned integers no longer works constexpr auto N = 64; std::bitset<N> b(0xDEADC0DE); // OK, direct initialization std::bitset<N> b = 0xDEADC0DE; // ERROR, copy

All the docs I've seen imply that you might be able to do that, but there isn't anything official w/r/t ulong64/uint64 fields. There are a few off-the-shelf options that look quite promising in this arena: BigIntegerField ... almost, but signed; PositiveIntegerField ... suspiciously 32-bit-looking; and DecimalField ... a fixed-pointer represented with a python decimal type, according to the docs -- which presumably turns into an analogously pedantic and slow database field when socked away, á la the DECIMAL or NUMERIC PostgreSQL types. ... all of which look like they might store a number like

From this question one could start to believe that alignment of a union is not less than the largest alignment of it's individual members. But I have a problem with the long long type in gcc/g++. The full example can be found here , but here are the relevant parts for my question: union ull { long long m; }; struct sll { long long m; }; int main() { #define pr(v) cout << #v ": " << (v) << endl pr(sizeof(long long)); pr(__alignof__(long long)); pr(sizeof(ull)); pr(__alignof__(ull)); pr(sizeof(sll)); pr(__alignof__(sll)); }; This results in the following output: sizeof(long long): 8 __alignof__

I have a problem while using the printf function to print values of type unsigned long long int I have no idea what's wrong. I'm using Dev-Cpp 4.9.9.2 and Visual Studio 2010 Professional (I know that it's not C compiler, but anyway, wanted to try) on Windows 7 Professional 64-bit. For displaying, I used %llu modifier (according to How do you printf an unsigned long long int(the format specifier for unsigned long long int)? ) but I also tried I64d with no effect... Firstly, I just wanted to print minimum and maximum value of unsigned long long int (using ULONG_MAX from limits.h ) printf(