Gem dependencies versions meaning

问题

Gem dependency version can be specified with prefixes =, <, >, <=, >= and ~>. I understand all except last one, what does ~> mean?

回答1:

The ~> operator means: match within the same version, depending on how specific you want it to be, here's some examples:

 Specification From  ... To (exclusive)
  ">= 3.0"      3.0   ... ∞
  "~> 3.0"      3.0   ... 4.0
  "~> 3.0.0"    3.0.0 ... 3.1
  "~> 3.5"      3.5   ... 4.0
  "~> 3.5.0"    3.5.0 ... 3.6

Source

来源：https://stackoverflow.com/questions/3492772/gem-dependencies-versions-meaning