Throw OverflowException when Multiply or Divide leaves the int exponent range - #120
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…nt range The result exponent was computed with unchecked int arithmetic, so 1e2000000000 squared wrapped to 1e-294967296, and integer Pow never threw the OverflowException it documents. The exponent is now checked, as the constructor and Parse already are. Fixes #109 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01M4xENzmZT4DZE8d5Hu6kEN
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This was referenced Sep 27, 2026
This was referenced Sep 28, 2026
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Fixes #109
What changed
The result exponent is now computed with
checked(...), the same way the constructor andParsealready do it. This covers:Multiply:left.Exponent + right.ExponentDivide:left.Exponent - right.ExponentTryDivideExactly:exponent - scaleDivideToPrecision:exponent - scaleandscaledExponent + excessMultiplyand bothDivideoverloads now documentOverflowException. IntegerPowgoes throughMultiply, so theOverflowExceptionit already documents is now actually thrown.Before this change,
1e2000000000 * 1e2000000000returned1e-294967296and(big * big) > bigwasfalse.Tests
TestMultiplyThrowsOverflowWhenTheExponentLeavesTheIntRange: coversbig * big,small * smallandPow(big, 2), and checks thatbig * small == 1is unaffected.TestDivideThrowsOverflowWhenTheExponentLeavesTheIntRange: coversbig / smallandsmall / big, and checks thatbig / big == 1is unaffected.TestDivideThrowsOverflowWhenScalingTheQuotientLeavesTheIntRange: covers the exact-quotient path (1E-2147483648 / 2) and the rounded path (/ 3, including an explicit precision).Verification
dotnet testsuite passes: 388/388.🤖 Generated with Claude Code
https://claude.ai/code/session_01M4xENzmZT4DZE8d5Hu6kEN
Generated by Claude Code