Add a BitMap struct #2710
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Add a BitMap struct #2710
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frangio
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Jun 8, 2021
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Code and tests look good to me.
frangio
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Jun 10, 2021
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Looks good, though I wonder if we also want a set(BitMap, uint256, bool) function. Could be useful in some cases.
Co-authored-by: Francisco Giordano <frangio.1@gmail.com>
frangio
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Jun 11, 2021
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Native bitmap are really storage inneficient:
mapping(X => bool)will use a new storage slot for each entrybool[]will use an underlyingbytes1[]array, which only truly uses 32 bits per 256 bits storage slot.This PR include a dense bitmap, that will save on gas when entries are consecutive. This design is used by Uniswap merkle-distributor to reduce the gas cost of writing to new (clean) storage slot by a factor 8 over what bool[] would have required.
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