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Diffstat (limited to 'docs/units-and-global-variables.rst')
| -rw-r--r-- | docs/units-and-global-variables.rst | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/docs/units-and-global-variables.rst b/docs/units-and-global-variables.rst index 6eae2804..28c9e6ab 100644 --- a/docs/units-and-global-variables.rst +++ b/docs/units-and-global-variables.rst @@ -96,13 +96,14 @@ Block and Transaction Properties .. index:: abi, encoding, packed -ABI Encoding Functions ----------------------- +ABI Encoding and Decoding Functions +----------------------------------- +- ``abi.decode(bytes encodedData, (...)) returns (...)``: ABI-decodes the given data, while the types are given in parentheses as second argument. Example: ``(uint a, uint[2] memory b, bytes memory c) = abi.decode(data, (uint, uint[2], bytes))`` - ``abi.encode(...) returns (bytes)``: ABI-encodes the given arguments - ``abi.encodePacked(...) returns (bytes)``: Performs :ref:`packed encoding <abi_packed_mode>` of the given arguments - ``abi.encodeWithSelector(bytes4 selector, ...) returns (bytes)``: ABI-encodes the given arguments starting from the second and prepends the given four-byte selector -- ``abi.encodeWithSignature(string signature, ...) returns (bytes)``: Equivalent to ``abi.encodeWithSelector(bytes4(keccak256(bytes(signature)), ...)``` +- ``abi.encodeWithSignature(string signature, ...) returns (bytes)``: Equivalent to ``abi.encodeWithSelector(bytes4(keccak256(bytes(signature))), ...)``` .. note:: These encoding functions can be used to craft data for function calls without actually @@ -152,7 +153,7 @@ Mathematical and Cryptographic Functions It might be that you run into Out-of-Gas for ``sha256``, ``ripemd160`` or ``ecrecover`` on a *private blockchain*. The reason for this is that those are implemented as so-called precompiled contracts and these contracts only really exist after they received the first message (although their contract code is hardcoded). Messages to non-existing contracts are more expensive and thus the execution runs into an Out-of-Gas error. A workaround for this problem is to first send e.g. 1 Wei to each of the contracts before you use them in your actual contracts. This is not an issue on the official or test net. -.. index:: balance, send, transfer, call, callcode, delegatecall +.. index:: balance, send, transfer, call, callcode, delegatecall, staticcall .. _address_related: Address Related @@ -170,6 +171,8 @@ Address Related issue low-level ``CALLCODE`` with the given payload, returns ``false`` on failure, forwards all available gas, adjustable ``<address>.delegatecall(bytes memory) returns (bool)``: issue low-level ``DELEGATECALL`` with the given payload, returns ``false`` on failure, forwards all available gas, adjustable +``<address>.staticcall(bytes memory) returns (bool)``: + issue low-level ``STATICCALL`` with the given payload, returns ``false`` on failure, forwards all available gas, adjustable For more information, see the section on :ref:`address`. |