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Return ±1 for -1 raised to an integer too large for an int [patch] - #153
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The integer-power loop counts the exponent down as an int, so (-1)^n threw OverflowException for |n| >= 2^31 although the result is always ±1. Answer -1 by the parity of the power before the loop, as +1 already is. Fixes #128 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JGKBe8wvU3P6jYj9MkNC69
…down SonarCloud S3776 flagged Pow at cognitive complexity 21 (limit 15) once the (-1)^n shortcut was added. The integer branch is now its own method; behaviour is unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JGKBe8wvU3P6jYj9MkNC69
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This was referenced Oct 6, 2026
This was referenced Oct 7, 2026
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Fixes #128
What changed
Powraises an integer power by repeated squaring, counting the exponent down as anint. An exponent with magnitude of 2^31 or more doesn't fit, so(-1)^nthrewOverflowExceptionfor those exponents, even though the result is always ±1.A base of +1 already returns early through
IsUnit. This adds the matching early return for −1 at the top of the integer branch:IsEvenInteger(power) ? One : NegativeOne.A fractional power of −1 still throws
ArgumentOutOfRangeException, as any negative base does. Any other base with an exponent that large still overflows the result's exponent, so that exception stays, as the issue asks.Tests
PowOfNegativeOneIsParityOfAnyIntegerPowercovers the three failing calls from the issue (2147483648,-2147483648,1e20), the odd values just past theintrange (±2147483649), and in-range values (2147483647,2,-3).PreciseNumber.cschange stashed, the five out-of-range cases fail. With it, all 448 tests pass.dotnet build -c Releaseof the library succeeds.🤖 Generated with Claude Code
https://claude.ai/code/session_01JGKBe8wvU3P6jYj9MkNC69
Generated by Claude Code