Add a way to determine whether a signal has listeners #995
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Some signals are actually quite expensive to assert. It would be helpful to be able to query a signal to determine whether it has listeners before doing work to try to invoke it.
yuwilbur
reviewed
Sep 16, 2016
| autowiring::signal<void()> s; | ||
| ASSERT_FALSE(s) << "Signal did not correctly report it had no listeners"; | ||
| s += [] {}; | ||
| ASSERT_TRUE(s) << "Signal stated that it had no listeners when it should have had at least one"; |
There was a problem hiding this comment.
Perhaps you can add one more additional use case such that:
auto listener = [] {};
auto registration = s += listener;
ASSERT_TRUE(s) << "Signal stated that it had no listeners when it should have had at least one";
s -= resgistration;
ASSERT_FALSE(s) << "Signal stated that it has listeners after removing all listeners";
|
Looks good! |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Some signals are actually quite expensive to assert. It would be helpful to be able to query a signal to determine whether it has listeners before doing work to try to invoke it.