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Diffstat (limited to 'docs/frequently-asked-questions.rst')
| -rw-r--r-- | docs/frequently-asked-questions.rst | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/docs/frequently-asked-questions.rst b/docs/frequently-asked-questions.rst index b1ca04ff..fc7d7b7f 100644 --- a/docs/frequently-asked-questions.rst +++ b/docs/frequently-asked-questions.rst @@ -666,21 +666,22 @@ gas and return your 20 Wei). In the above example, the low-level function `call` is used to invoke another contract with `p.data` as payload and `p.amount` Wei is sent with that call. -What happens to a mapping copied from a mapping of structs? -=========================================================== +What happens to a struct's mapping when copying over a struct? +============================================================== This is a very interesting question. Suppose that we have a contract field set up like such:: struct user{ mapping(string => address) usedContracts; } - mapping(uint => user) userList; function somefunction{ - user userA = userList[1]; - userList[2] = userA; + user user1; + user1.usedContracts["Hello"] = "World"; + user user2 = user1; } -In this case, the mapping of the struct being copied over into the userList is ignored. +In this case, the mapping of the struct being copied over into the userList is ignored as there is no "list of mapped keys". +Therefore it is not possible to find out which values should be copied over. How do I initialize a contract with only a specific amount of wei? ================================================================== |