Referencing local variable before assignment results in unexpected behavior

[kristoffer.carlsson]

@sijo

We can also write [&]{ ... } to capture all necessary variables by reference (approximately equivalent to the Julia behavior), and [=]{ ... } to capture them by copy.

I suggested something along the lines of C++ capture list a long time ago Explicit capture of variables in a closure. · Issue #14959 · JuliaLang/julia · GitHub. Probably not a good idea though.