Unfortunately, as of 5.8.0, that still doesn't work properly.
perl> print join "\n", map{ \substr 'The quick brown fox', $_ } 0 ..
+19
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
LVALUE(0x15d7cf4)
As you can see, each time you take an Lvalue from substr, it re-uses the same address. So you end up with and array of pointers to the last char in the string.
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller