Explain address payable and withdraw.

This commit is contained in:
chriseth 2018-09-27 11:16:50 +02:00
parent 9508406984
commit 927cdb3170
2 changed files with 11 additions and 1 deletions

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@ -107,7 +107,10 @@ For most of the topics the compiler will provide suggestions.
other way around is not allowed. Converting ``address`` to ``address
payable`` is possible via conversion through ``uint160``. If ``c`` is a
contract, ``address(c)`` results in ``address payable`` only if ``c`` has a
payable fallback function.
payable fallback function. If you use the :ref:`withdraw pattern<withdrawal_pattern>`,
you most likely do not have to change your code because ``transfer``
is only used on ``msg.sender`` instead of stored addresses and ``msg.sender``
is an ``address payable``.
* Conversions between ``bytesX`` and ``uintY`` of different size are now
disallowed due to ``bytesX`` padding on the right and ``uintY`` padding on

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@ -189,6 +189,13 @@ has the type ``address payable``, if ``x`` is of integer or fixed bytes type, a
If ``x`` is a contract without payable fallback function, then ``address(x)`` will be of type ``address``.
In external function signatures ``address`` is used for both the ``address`` and the ``address payable`` type.
.. note::
It might very well be that you do not need to care about the distinction between ``address``
and ``address payable`` and just use ``address`` everywhere. For example,
if you are using the :ref:`withdrawal pattern<withdrawal_pattern>`, you can (and should) store the
address itself as ``address``, because you invoke the ``transfer`` function on
``msg.sender``, which is an ``address payable``.
Operators:
* ``<=``, ``<``, ``==``, ``!=``, ``>=`` and ``>``