MultiToken v1.1.0

Changes

• function safeTransferFrom is used for transferring ERC721 tokens (previously transferFrom)

New functions

• isValid - checks that internal rules applies for asset:
  • ERC20 id has to be 0
  • ERC721 amount has to be 1
  • amount has to be >0 for any category
• isSameAs - check that given struct are representing the same asset (could vary in amount)