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An arena aligns block size instead of its starting address · case 03

An allocation starts at a misaligned cursor even though its padded size is a multiple of alignment.

Member previewVariant 3 · 3 implementations · 7 checks per implementation

Case contract

Cursor and sizes are nonnegative integers; each requested alignment is a positive integer, not necessarily a power of two. Return [starting addresses,final cursor]. Each start is the least aligned address >= cursor, then cursor becomes start+size. Zero-size reservations may consume alignment padding.

Why this case matters

Models address arithmetic in an arena allocator without dereferencing memory, and exposes both misalignment and unnecessary padding independent of machine word size.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
unaligned starting cursor	`[[25], 33]`	`[[32], 35]`	Failed

MEMBER ARCHIVE

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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