The fact that these casts are unnecessary can be tracked using comments, a list of issues in STATUS, or, not wishing to rock the boat, bugzilla. Using a macro just obfuscates the code.
s/unnecessary/undesirable/
I hardly think it is more obfuscating that any macro might be considered to be. The only reasonable alternative in my opinion would be to add a comment line for each cast with some common grep-able string. But to me that is uglier.
