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Hi David,

I'm not sure if I understand your problem ...

... the call foo("a") is exactly doing what I expect, i.e. @_ == 1

Anything else - like pushing an optional $that into @_ - wouldn't really be backwards compatible.

And the number you seem to want is static, it's the sum of obligatory arguments + defaulted ones.

(maybe you want to make a feature request to be able to introspect the signature)

FWIW, when interested you can look into the implementation with B::Deparse ...

# use strict; use warnings; use feature qw(signatures); no warnings qw(experimental::signatures); use B::Deparse; use Test::More; sub foo ($this, $that='bar') { return scalar @_; } is( foo(1), 1, "one arg" ); is( foo(1,2), 2, "two args" ); done_testing(); warn "Show implementation:\n", B::Deparse->new()->coderef2text(\&foo);

C:/Perl_524/bin\perl.exe -w d:/exp/ ok 1 - one arg ok 2 - two args 1..2 Show implementation: { BEGIN {${^WARNING_BITS} = "\x54\x55\x55\x55\x55\x55\x55\x55\x55\x5 +5\x55\x55\x55\x55\x54\x55\x05"} use strict; use feature 'signatures'; die sprintf("Too many arguments for subroutine at %s line %d.\n", +(caller)[1, 2]) unless @_ <= 2; die sprintf("Too few arguments for subroutine at %s line %d.\n", ( +caller)[1, 2]) unless @_ >= 1; my $this = $_[0]; my $that = @_ >= 2 ? $_[1] : 'bar'; (); return scalar @_; } at d:/exp/ line 32. Compilation finished at Tue Jul 14 14:25:41

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery


expanded code with tests

In reply to Re: Contents of @_ using subroutine signatures with default values (not a bug) by LanX
in thread Contents of @_ using subroutine signatures with default values by davido

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