in reply to Re^5: Constant subroutine main::C redefined
in thread Constant subroutine main::C redefined

C:\test>perl -wE"no warnings 'redefine';sub FOO(){23};sub FOO(){42};sa
+y $];"
Constant subroutine FOO redefined at -e line 1.
5.014002

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With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

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Re^7: Constant subroutine main::C redefined
by toolic (Bishop) on Sep 10, 2012 at 12:50 UTC
    Not sure if it helps, but diagnostics shows: 
    Constant subroutine FOO redefined at -e line 1 (#1)
    (S) You redefined a subroutine which had previously been
    eligible for inlining.  See perlsub/"Constant Functions" for
    commentary and workarounds.

    [download]

    Leading to Constant Functions, which mentions a workaround.

[reply]
[d/l]

      Tried that also :( 

      C:\test>perl -wE"no warnings 'redefine';sub FOO(){23};sub FOO(){42 if 
+$];};say$];"
Constant subroutine FOO redefined at -e line 1.
5.014002

      [download]

      Dropping the prototype isn't an option either because the constant getting redefined is a very rare occurence (but one that must be catered for), and I don't want to lose the benefits of compile time optimisations for the majority of cases.

      If a constant sub is redefined to be the same value, it doesn't cause the warning:

      C:\test>perl -wE"no warnings 'redefine';sub FOO(){23};sub FOO(){23};sa
+y$];"
5.014002

      [download]

      which will be the majority of cases, but I cannot predict when the edge case might occur so I have to try the redefinition in all cases.

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.

      RIP Neil Armstrong
      /div
[reply]
[d/l]
[select]
        so what about delete $main::{C}? did you try?
[reply]
[d/l]

        You need the if $] in the first definition of FOO. That should prevent it being constant-folded.

        perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'
[reply]
[d/l]

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