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sub mapfirst {
    my( $sub )= shift( @_ );
...
sub addten { $_ += 10  for @_ }
mapfirst( \&addten, \@a, \@b, \@c );
mapfirst( sub { print "@_\n" }, \@a, \@b, \@c );

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    if( 0 == @_ ) {
        &$sub();
...
        &$sub( $_[0][0], $_[1][0], $_[2][0] );
    # etc to some arbitrary maximum number of arguments
    }

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    eval "&\$sub( " . join( ", ", map "\$_[$_][0]", 0..$#_ ) . " )"

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    $av= sub { \@_ }->( @$av, $_->[0] )   for  @_;

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sub mapfirst {
    my( $sub )= shift( @_ );
...
sub addten { $_ += 10  for @_ }
mapfirst( \&addten, \@a, \@b, \@c );
mapfirst( sub { print "@_\n" }, \@a, \@b, \@c );

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```
    ( $x, $y )= ( $y, $x );
```

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sub swapPairs { @_[ map $_^1, 0..$#_ ]= @_ }

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```
    $_= $something  for @_;
```

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use Algoritm::Loops 'MapCarE';
sub swapValues { MapCarE { $_[0]= $_[1] } \@_, [reverse @_] }