fix: level!
macros with constant field names in the first position
#2883
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Outdated suggestions cannot be applied.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.
Motivation
#2837
Const argumetns in
level!
macros do not work when in the first positoin.This also seems to have fixed #2748 where literals for fields names like
info!("foo" = 2)
could not be used outside theevent!
macro.Solution
Previsously,
level!($(args:tt))
was forwarded toevent!(target: ..., level: ..., { $(args:tt) })
but the added curly braces seem to have prevented theevent
macro from correctly understanding the arguments and it tried to pass them toformat!
.With this change there may have some performance impact when expanding the macros in most cases where the braces could have been added as it will take one more step.
These are the two relevant
event!
blocks I believe, the new tests used to expand to the first one (with empty fields), now they expand to the latter: