I want to know if there exists an idiom that conveys the meaning of
one solution fitting all problems in all scenarios?
What swim into my mind are two phrases: 1) silver bullet, 2) one size fits all. For the former, I thought it is more of the complexity of the problem than the scope of problems; while for the later I thought it is better but concentrates more on size. In the Chinese world the phrase would be "放之四海而皆准" meaning that a rule or solution can apply to any situation worldwide.
Any more native expressions for that?