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Re^2: Inline::C : passing parameters to functions, modifying by reference

by bliako (Monsignor)
on Jul 23, 2021 at 08:36 UTC ( #11135336=note: print w/replies, xml ) Need Help??


in reply to Re: Inline::C : passing parameters to functions, modifying by reference
in thread Inline::C : passing parameters to functions, modifying by reference

Anonmonk, here is how but I can't see how this is related to Inline::C.

Case2 (pass a scalar - not a ref) is obviously failing. But I don't think that should apply to Inline::C because AFAICT a scalar, like a scalarref and any ref, is passed as an SV * which I can affect its PV field within func() and insert an arrayref in there. A good warmup though thanks.

use strict; use warnings; use Test::More; use Data::Dumper; my $correct_result = make_a_rowsxcols_array(5,3); print Dumper($correct_result); ### $#out = -1; # clears an array; # Case1: pass it an arrayref my $T = 'Case1'; my @out = (1,2,3); is( case1(\@out), 0, "$T: returned success."); is_deeply(\@out, $correct_result, "$T: correct result."); # Case2: pass it a scalar $T = 'Case2'; my $x = 123; is( case2($x), 0, "$T: returned success."); is_deeply($x, $correct_result, "$T: correct result."); # Case3: pass it a scalarref $T = 'Case3'; my $y = 123; is( case3(\$y), 0, "$T: returned success."); is_deeply($y, $correct_result, "$T: correct result."); done_testing(); sub case1 { # pass an arrayref, clear it and make it 5rowsx3cols my $out = $_[0]; return 1 unless ref($out) eq 'ARRAY'; $#{ $out } = -1; push @$out, @{ make_a_rowsxcols_array(5,3) }; return 0; } sub case2 { # pass a simple scalar, make it an arrayref my $out = $_[0]; return 1 unless ref($out) eq ''; $out = make_a_rowsxcols_array(5,3); return 0; } sub case3 { # pass a scalarref, fill it with an arrayref to 5rowsx3cols my $out = $_[0]; return 1 unless ref($out) eq 'SCALAR'; undef $$out; $$out = make_a_rowsxcols_array(5,3); return 0; } sub make_a_rowsxcols_array { [ map { [ (42)x$_[1] ] } 1..$_[0] ] }

bw, bliako

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