Gotta be careful not to break 

>perl -le"$x='abc'; (substr($x,0,1) = 'd') =~ s/(.)/uc $1/e; print $x"
Dbc

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In reply to Re^2: Bug or WAD in lvalue substr? (against) by ikegami
in thread Bug or WAD in lvalue substr? (again.) by BrowserUk

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