what does ~> mean in gemspec dependencies?

Question

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Meaning of tilde-greater-than (~>) in version requirement?

I see something like this a lot in gemspecs:

s.add_dependency 'some_gem', '~> 1.5.0'

What does ~> mean?

Answer 1

From gembundler

The specifier ~> has a special meaning, best shown by example. 
~> 2.0.3 is identical to >= 2.0.3 and < 2.1. 
~> 2.1 is identical to >= 2.1 and < 3.0. 
~> 2.2.beta will match prerelease versions like 2.2.beta.12.