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GetCommonAncestorLevel: work around bit_width return type bug#431

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jmr merged 3 commits intogoogle:masterfrom
idevtm:fix-bit_width-unsigned
May 20, 2025
Merged

GetCommonAncestorLevel: work around bit_width return type bug#431
jmr merged 3 commits intogoogle:masterfrom
idevtm:fix-bit_width-unsigned

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@idevtm idevtm commented May 19, 2025 •
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This is meant to work around the situation when absl::bit_width is unsigned long.

error: no matching function for call to 'max'
[build]   return max(61 - absl::bit_width(bits), -1) >> 1;
[build]          ^~~
[build] /usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/algorithmfwd.h:407:5: note: candidate template ignored: deduced conflicting types for parameter '_Tp' ('unsigned long' vs. 'int')

ref abseil/abseil-cpp#1890
ref #421 (comment)

System: Debian 12
Compiler: Clang-15

@idevtm idevtm marked this pull request as ready for review May 19, 2025 15:57
@jmr jmr changed the title Fix type conversion in GetCommonAncestorLevel for bit width calculation GetCommonAncestorLevel: work around bit_width return type bug May 19, 2025
jmr added 2 commits May 19, 2025 21:09
@jmr
s2cell_id.cc: Add comment and move cast
b32a122 
Add comment to document workaround.

Move cast.  It's the `bit_width` return value that is wrong, so cast that.
@jmr
Fix line length
ef01b21
@jmr jmr merged commit 473a989 into google:master May 20, 2025
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@BrewTestBot BrewTestBot mentioned this pull request Dec 1, 2025
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@idevtm @jmr @stefankarschti