c# - Why doesn't Enumerable.Cast<> use my conversion operator? -

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using type:

class foo {   public static implicit operator int(foo obj)   {     return 5;   } }  var test=new[] { new foo() };

the following works expected

var ok=test.select(x => (int)x).tolist();

but using cast<> fails invalidcastexception - why?

var fail=test.cast<int>().tolist();

read jon skeet's blog reimplementing linq (edulinq), part 33, says this:

it's worth noting (as of .net 3.5 sp1) cast , oftype perform reference , unboxing conversions. won't convert boxed int long, or execute user-defined conversions. follow same rules converting object generic type parameter. (that's convenient implementation!)


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