From @masak

<Util> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X* 5;
say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«[1, 2, 3]␤[5, 10, 15]␤»
<Util> Should X*= have worked? If not, how to best scale a vector
without repeating the vector's array name?
<masak> @​b = @​a X* 5
<masak> :P
<masak> and yes, I think X*= should have worked.
* masak submits rakudobug
<tylercurtis> rakudo​: my @​a = 1, 2, 3; @​a [X*]= 5; say @​a.perl; @​a =
@​a X* 5; say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«===SORRY!===␤Confused at line 22, near
"@​a [X*]= 5"␤»
<Util> S03 discusses X[+=] vs [X+]= in "Nesting of metaoperators", but
X[*=] does the same as X*= , and [X*]= fails.
<Util> Oh, as tylercurtis just showed.

From @coke

On Thu Sep 02 20​:55​:52 2010, masak wrote​:

<Util> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X* 5;
say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«[1, 2, 3]␤[5, 10, 15]␤»
<Util> Should X*= have worked? If not, how to best scale a vector
without repeating the vector's array name?
<masak> @​b = @​a X* 5
<masak> :P
<masak> and yes, I think X*= should have worked.
* masak submits rakudobug
<tylercurtis> rakudo​: my @​a = 1, 2, 3; @​a [X*]= 5; say @​a.perl; @​a =
@​a X* 5; say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«===SORRY!===␤Confused at line 22, near
"@​a [X*]= 5"␤»
<Util> S03 discusses X[+=] vs [X+]= in "Nesting of metaoperators", but
X[*=] does the same as X*= , and [X*]= fails.
<Util> Oh, as tylercurtis just showed.

This now fails outright​:

19​:25 < [Coke]> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X*
  5;say @​a.perl;
19​:25 <+p6eval> rakudo 38907e​: OUTPUT«Array.new(1, 2, 3)␤splice() not
  implemented in class 'Mu'␤ in method reify at
  src/gen/CORE.setting​:3657␤ in method gimme at
  src/gen/CORE.setting​:4015␤ in method eager at
  src/gen/CORE.setting​:3991␤ in method STORE at
  src/gen/CORE.setting​:4409␤ in block <anon> a…

--
Will "Coke" Coleda

The RT System itself - Status changed from 'new' to 'open'

From @coke

On Mon Oct 10 16​:25​:45 2011, coke wrote​:

On Thu Sep 02 20​:55​:52 2010, masak wrote​:

<Util> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X* 5;
say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«[1, 2, 3]␤[5, 10, 15]␤»
<Util> Should X*= have worked? If not, how to best scale a vector
without repeating the vector's array name?
<masak> @​b = @​a X* 5
<masak> :P
<masak> and yes, I think X*= should have worked.
* masak submits rakudobug
<tylercurtis> rakudo​: my @​a = 1, 2, 3; @​a [X*]= 5; say @​a.perl; @​a =
@​a X* 5; say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«===SORRY!===␤Confused at line 22, near
"@​a [X*]= 5"␤»
<Util> S03 discusses X[+=] vs [X+]= in "Nesting of metaoperators", but
X[*=] does the same as X*= , and [X*]= fails.
<Util> Oh, as tylercurtis just showed.

This now fails outright​:

19​:25 < [Coke]> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X*
5;say @​a.perl;
19​:25 <+p6eval> rakudo 38907e​: OUTPUT«Array.new(1, 2, 3)␤splice() not
implemented in class 'Mu'␤ in method reify at
src/gen/CORE.setting​:3657␤ in method gimme at
src/gen/CORE.setting​:4015␤ in method eager at
src/gen/CORE.setting​:3991␤ in method STORE at
src/gen/CORE.setting​:4409␤ in block <anon> a…

Output is now close to the OP​:

my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X* 5;say @​a.perl;
Array.new(1, 2, 3)
Array.new(5, 10, 15)

--
Will "Coke" Coleda

From @Mouq

On Sun Oct 21 06​:35​:20 2012, coke wrote​:

On Mon Oct 10 16​:25​:45 2011, coke wrote​:

On Thu Sep 02 20​:55​:52 2010, masak wrote​:

<Util> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X*
5;
say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«[1, 2, 3]␤[5, 10, 15]␤»
<Util> Should X*= have worked? If not, how to best scale a vector
without repeating the vector's array name?
<masak> @​b = @​a X* 5
<masak> :P
<masak> and yes, I think X*= should have worked.
* masak submits rakudobug
<tylercurtis> rakudo​: my @​a = 1, 2, 3; @​a [X*]= 5; say @​a.perl; @​a

@​a X* 5; say @​a.perl;
<p6eval> rakudo 33e94e​: OUTPUT«===SORRY!===␤Confused at line 22,
near
"@​a [X*]= 5"␤»
<Util> S03 discusses X[+=] vs [X+]= in "Nesting of metaoperators",
but
X[*=] does the same as X*= , and [X*]= fails.
<Util> Oh, as tylercurtis just showed.

This now fails outright​:

19​:25 < [Coke]> rakudo​: my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a =
@​a X*
5;say @​a.perl;
19​:25 <+p6eval> rakudo 38907e​: OUTPUT«Array.new(1, 2, 3)␤splice() not
implemented in class 'Mu'␤ in method reify at
src/gen/CORE.setting​:3657␤ in method gimme at
src/gen/CORE.setting​:4015␤ in method eager at
src/gen/CORE.setting​:3991␤ in method STORE at
src/gen/CORE.setting​:4409␤ in block <anon> a…

Output is now close to the OP​:

my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X* 5;say @​a.perl;
Array.new(1, 2, 3)
Array.new(5, 10, 15)

Looks fixed​:

perl6 -e'my @​a = 1, 2, 3; @​a X*= 5; say @​a.perl; @​a = @​a X* 5; say @​a.perl;'
Array.new(5, 10, 15)
Array.new(25, 50, 75)

As well, S03-metaops/cross.t has a test making sure that X*= modifies the container, so I'm marking this as resolved

@Mouq - Status changed from 'open' to 'resolved'