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LayerXcom / verified-vyper-contracts

FVyper: A collection of useful Vyper contracts developed with formal methods
Apache License 2.0
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[ERC721] Double SSTORE because of `_removeTokenFrom` in transfer #25

Open nrryuya opened 5 years ago

nrryuya commented 5 years ago

_removeTokenFrom is used in both burn and _doTransfer but it's not efficient because SSTORE executed twice in transfer.

https://github.com/LayerXcom/verified-vyper-contracts/blob/fca925befdc4c5c296c95e8df99db31426aeac48/erc721/ERC721.vy#L194