Helper method to coerce a value into a specific class. Raises a TypeError if the coercion fails or the returned
value is not of the right class. (from Rubinius)
# File lib/matrix.rb, line 1527
def self.coerce_to(obj, cls, meth) # :nodoc:
return obj if obj.kind_of?(cls)
raise TypeError, "Expected a #{cls} but got a #{obj.class}" unless obj.respond_to? meth
begin
ret = obj.__send__(meth)
rescue Exception => e
raise TypeError, "Coercion error: #{obj.inspect}.#{meth} => #{cls} failed:\n" "(#{e.message})"
end
raise TypeError, "Coercion error: obj.#{meth} did NOT return a #{cls} (was #{ret.class})" unless ret.kind_of? cls
ret
end
