array_view: explicitly initialize constexpr function variables
array_view: explicitly initialize constexpr function variables
matus-chochlik/GSL,neilmacintosh/GSL,nguarracino/GSL,garyfurnish/GSL,martinmoene/GSL,bashrc-real/GSL,jbcoe/GSL,vladon/GSL,Josaphat/GSL,kernhanda/GSL