java - More relaxed restriction in wildcard instantiations than in declaration -


consider following class:

class a<t extends number> { }

i wonder why line compile successfully? 

a<? extends object> = new a<integer>();

while piece of code not

class b {   static <t extends object> void m(a<t> a) {} }

in both cases compiler "knows" range ? extends object on range ? extends number declaration of type a accepts 1st , rejects 2nd.

is there in java language or jvm specifications?


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