Why is the block form of class_eval preferable? about ruby-style-guide

[pangloss]

I'll add @mrflip here since I just noticed his comment in #46

[bbatsov]

My rationale is quite simple - string manipulation is inherently fragile + it represents security risk if you're dealing with user input. Obviously there are situations where it makes sense to use strings with class_eval/instance_eval, but that should be the exception, not the norm.

[fuadsaud]

Not exactly the same issue, but this is a worth reading on the class_eval subject.

http://tenderlovemaking.com/2013/03/03/dynamic_method_definitions.html