& was once used as a unary operator in ccall and therefore had to be parsed differently. That use was deprecated for Julia 0.7 and according to deprecate `&x` syntax in ccall, replace with Ref · Issue #6080 · JuliaLang/julia · GitHub the plan was to change the parsing for 1.0 but it seems that didn’t happen. I’ve opened an issue to revisit this: Parse `&x`as a call expression · Issue #34693 · JuliaLang/julia · GitHub.
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