Drop redundant Widen operator from RHS of subtyping rule#130
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nikitabobko wants to merge 1 commit into
Open
Drop redundant Widen operator from RHS of subtyping rule#130nikitabobko wants to merge 1 commit into
nikitabobko wants to merge 1 commit into
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Statement 1: if (Widen(X) <: Widen(Y)) is true expression then Widen(X) <: Y stays true expression
Statement 2: There is no such X and Y that the both following expressions evaluate to true
Widen(X) <: Widen(Y) is false
Widen(X) <: Y is true
In general case, statement 2 is not valid
In our specific case where Widen is defined the way it's defined,
statement 2 is valid
Given that in our case statement 1 and statement 2 are both valid, Widen
is redundant in the RHS and confuses readers
Informally: the intention is to make the widened type more appealing for
the overload resolution, so only LHS should be widened
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Statement 1. if (Widen(X) <: Widen(Y)) is true expression then Widen(X) <: Y stays true expression
Statement 2. There is no such X and Y that the both following expressions evaluate to true
In general case, statement 2 is not valid. In our specific case where Widen is defined the way it's defined, statement 2 is valid
Given that in our case statement 1 and statement 2 are both valid, Widen is redundant in the RHS and confuses readers
Informally: the intention is to make the widened type more appealing for
the overload resolution, so only LHS should be widened