How to compare two typedesc in a pattern for equality
I would like to be able to compare two typedesc in a template to see if they refer to the same type (or at least have the same type name), but I'm not sure how. The operator ==
does not allow this.
type
Foo = object
Bar = object
template test(a, b: expr): bool =
a == b
echo test(Foo, Foo)
echo test(Foo, Bar)
This gives me the following:
Error: type mismatch: got (typedesc[Foo], typedesc[Foo])
How can I do that?
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1 answer
Operator is
helps: http://nim-lang.org/docs/manual.html#generics-is-operator
type
Foo = object
Bar = object
template test(a, b: expr): bool =
#a is b # also true if a is subtype of b
a is b and b is a # only true if actually equal types
echo test(Foo, Foo)
echo test(Foo, Bar)
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