Module utils 

Numerical and timing utilities.

Mirrors Common/IpUtils.{hpp,cpp}. The PRNG is a portable reimplementation of POSIX drand48 (48-bit LCG with the glibc-default seed) so output matches a drand48-built upstream Ipopt deterministically. Replace with libc’s drand48 later if a particular platform’s bit-equivalence target requires it.

Functions

compare_le

Equivalent to Ipopt::Compare_le(lhs, rhs, BasVal) — relaxed <= with a tolerance proportional to |BasVal|. Threshold matches upstream’s (10 * machine_epsilon * Max(1, |BasVal|)).

compute_mem_increase_i64

Equivalent to Ipopt::ComputeMemIncrease. Updates len to a new length consistent with recommended/min while clamping to T::MAX. Returns Err if even the maximum representable size would not be an increase.

cpu_time

CPU time in seconds. Equivalent to Ipopt::CpuTime.

ip_random_01

Equivalent to Ipopt::IpRandom01. 48-bit LCG matching POSIX drand48: X_{n+1} = (0x5DEECE66D · X_n + 0xB) mod 2^48, returning the high-order 48 bits as a f64 in [0, 1).

ip_reset_random_01

Reset the PRNG to glibc’s default seed. Equivalent to Ipopt::IpResetRandom01.

is_finite_number

Equivalent to Ipopt::IsFiniteNumber. Returns false for NaN/±∞.

sys_time

System time in seconds since UNIX epoch. Equivalent to Ipopt::SysTime.

wallclock_time

Wallclock time in seconds since first call. Equivalent to Ipopt::WallclockTime.