1 files changed, 30 insertions, 0 deletions
diff --git a/lib/rubygems/win_platform.rb b/lib/rubygems/win_platform.rb
new file mode 100644
index 0000000000..10556871b2
--- /dev/null
+++ b/lib/rubygems/win_platform.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require "rbconfig"
+
+module Gem
+  ##
+  # An Array of Regexps that match windows Ruby platforms.
+
+  WIN_PATTERNS = [
+    /bccwin/i,
+    /djgpp/i,
+    /mingw/i,
+    /mswin/i,
+    /wince/i,
+  ].freeze
+
+  @@win_platform = nil
+
+  ##
+  # Is this a windows platform?
+
+  def self.win_platform?
+    if @@win_platform.nil?
+      ruby_platform = RbConfig::CONFIG["host_os"]
+      @@win_platform = !WIN_PATTERNS.find {|r| ruby_platform =~ r }.nil?
+    end
+
+    @@win_platform
+  end
+end