diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/control-structures.rst | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/docs/control-structures.rst b/docs/control-structures.rst index 7c91cab7..157dd531 100644 --- a/docs/control-structures.rst +++ b/docs/control-structures.rst @@ -400,17 +400,17 @@ If used properly, analysis tools can evaluate your contract to identify the cond There are two other ways to trigger exceptions: The ``revert`` function can be used to flag an error and revert the current call. It is possible to provide a string message containing details about the error that will be passed back to the caller. -The deprecated keyword ``throw`` can also be used as an alternative to ``revert()`` (but only without error message). .. note:: - From version 0.4.13 the ``throw`` keyword is deprecated and will be phased out in the future. + There used to be a keyword called ``throw`` with the same semantics as ``revert()`` which + whas deprecated in version 0.4.13 and removed in version 0.5.0. When exceptions happen in a sub-call, they "bubble up" (i.e. exceptions are rethrown) automatically. Exceptions to this rule are ``send`` -and the low-level functions ``call``, ``delegatecall``, ``callcode`` and ``staticcall`` -- those return ``false`` in case +and the low-level functions ``call``, ``delegatecall`` and ``staticcall`` -- those return ``false`` as their first return value in case of an exception instead of "bubbling up". .. warning:: - The low-level ``call``, ``delegatecall``, ``callcode`` and ``staticcall`` will return success if the called account is non-existent, as part of the design of EVM. Existence must be checked prior to calling if desired. + The low-level functions ``call``, ``delegatecall`` and ``staticcall`` return ``true`` as their first return value if the called account is non-existent, as part of the design of EVM. Existence must be checked prior to calling if desired. Catching exceptions is not yet possible. @@ -447,7 +447,6 @@ An ``assert``-style exception is generated in the following situations: A ``require``-style exception is generated in the following situations: -#. Calling ``throw``. #. Calling ``require`` with an argument that evaluates to ``false``. #. If you call a function via a message call but it does not finish properly (i.e. it runs out of gas, has no matching function, or throws an exception itself), except when a low level operation ``call``, ``send``, ``delegatecall``, ``callcode`` or ``staticcall`` is used. The low level operations never throw exceptions but indicate failures by returning ``false``. #. If you create a contract using the ``new`` keyword but the contract creation does not finish properly (see above for the definition of "not finish properly"). |