I have a fairly large code-base that relies on Method::Signatures, and I have found that it works very well. However, it depends on Devel::Declare. The documentation for Devel::Declare states, 
WARNING

Warning: Devel::Declare is a giant bag of crack originally implemented
+ by mst with the goal of upsetting the perl core developers so much b
+y its very existence that they implemented proper keyword handling in
+ the core.

As of perl5 version 14, this goal has been achieved, and modules such 
+as Devel::CallParser, Function::Parameters, and Keyword::Simple provi
+de mechanisms to mangle perl syntax that don't require hallucinogenic
+ drugs to interpret the error messages they produce.

[download]
So, for new code I would recommend Function::Parameters.

Also, it looks like the author of Method::Signatures (schwern) would like for the two modules to work well together. See these github issues,

However, these issues are a few years old and I don't know how much progress has been made in addressing them.

In reply to Re^2: sub variables by kevbot
in thread sub variables by Todd Chester

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