limits

As an experiment, I just put together some code to generate a std::array<uint32_t, 256> at compile time. The table contents themselves are a fairly typical CRC lookup table - about the only new thing is the use of constexpr functions to calculate the entries as opposed to putting an autogenerated magic table directly in the source code. Anyway, this exercise got me curious: would there be any practical limitations on the amount of computation a compiler would be willing to do to evaluate a constexpr function or variable definition at compile time? e.g. something like gcc's -ftemplate-depth

I was reading Setting an int to Infinity in C++ . I understand that when one needs true infinity, one is supposed to use numeric_limits<float>::infinity() ; I guess the rationale behind it is that usually integral types have no values designated for representing special states like NaN , Inf , etc. like IEEE 754 floats do (again C++ doesn't mandate neither - int & float used are left to the implementation); but still it's misleading that max > infinity for a given type. I'm trying to understand the rationale behind this call in the standard. If having infinity doesn't make sense for a type,

We need to raise RLIMIT_NOFILE when running memcached, as we're hitting the default hard limit (1024). However, raising a hard limit requires root, and for various reasons we don't want to have to run memcached or its containing shell as root. Right now we happily run it as a non-root user. Is there a way to raise the hard limit for RLIMIT_NOFILE system-wide, so that we can continue to run memcached as non-root and simply raise the soft limit? This is RedHat Linux with 2.6 kernel. Thanks! Jon You can set the limits in /etc/security/limits.conf with the syntax: <domain> <type> <item> <value>

I am trying to compile a C program in Ubuntu 10.04 made for 8.04. It fails because we have used PATH_MAX and other constants that should be defined in limits.h . According to various resources, it should be part of a POSIX compatible C library. Is this a bug in Ubuntu 10.04 or is there a proper way of solving this? POSIX defines many such limits to be optional. If a limit FOO is not defined in limits.h , it means the system may have no such limit or the limit might vary at runtime or dependent upon the pathname it's applied to. In these cases, you use the pathconf , fpathconf , or sysconf

What happen when SQL Server 2005 happen to reach the maximum for an IDENTITY column? Does it start from the beginning and start refilling the gap? What is the behavior of SQL Server 2005 when it happen? You will get an overflow error when the maximum value is reached . If you use the bigint datatype with a maximum value of 9,223,372,036,854,775,807 this will most likely never be the case. The error message you will get, will look like this: Msg 220, Level 16, State 2, Line 10 Arithmetic overflow error for data type tinyint, value = 256. (Source) As far as I know MS SQL provides no