FFI::C::ArrayDef - Array data definition for FFI

Author

       Graham Ollis <plicease@cpan.org>

Constructor

new
        my $def = FFI::C::ArrayDef->new(%opts);
        my $def = FFI::C::ArrayDef->new($ffi, %opts);

       For standard def options, see FFI::C::Def.

       members
           This should be an array reference the member type, and optionally the number of elements.  Examples:

            my $struct = FFI::C::StructDef->new(...);

            my $fixed = FFI::C::ArrayDef->new(
              members => [ $struct, 10 ],
            );

            my $var = FFI::C::ArrayDef->new(
              members => [ $struct ],
            );

Copyright And License

       This software is copyright (c) 2020-2022 by Graham Ollis.

       This  is  free  software;  you  can  redistribute  it and/or modify it under the same terms as the Perl 5
       programming language system itself.

perl v5.36.0                                       2023-02-06                              FFI::C::ArrayDef(3pm)

Description

       This class creates a def for a C array of structured data.  Usually the def contains a FFI::C::StructDef
       or FFI::C::UnionDef and optionally a number of elements.

Methods

create
        my $instance = $def->create;
        my $instance = $def->class->new;          # if class was specified
        my $instance = $def->create($count);
        my $instance = $def->class->new($count);  # if class was specified
        my $instance = $def->create(\@init);
        my $instance = $def->class->new(\@init);  # if class was specified

       This  creates an instance of the array.  If $count is given, this is used for the element count, possibly
       overriding what was specified when the def was created.   If  the  def  doesn't  have  an  element  count
       specified, then you MUST provide it here.  Returns a FFI::C::Array.

       You can optionally initialize member values using @init.

Name

       FFI::C::ArrayDef - Array data definition for FFI

Synopsis

       In your C code:

        #include <stdio.h>

        typedef struct {
          double x, y;
        } point_t;

        void
        print_rectangle(point_t rec[2])
        {
          printf("[[%g %g] [%g %g]]\n",
            rec[0].x, rec[0].y,
            rec[1].x, rec[1].y
          );
        }

       In your Perl code:

        use FFI::Platypus 1.00;
        use FFI::C::ArrayDef;
        use FFI::C::StructDef;

        my $ffi = FFI::Platypus->new( api => 1 );
        # See FFI::Platypus::Bundle for how bundle works.
        $ffi->bundle;

        my $point_def = FFI::C::StructDef->new(
          $ffi,
          name  => 'point_t',
          class => 'Point',
          members => [
            x => 'double',
            y => 'double',
          ],
        );

        my $rect_def = FFI::C::ArrayDef->new(
          $ffi,
          name    => 'rectangle_t',
          class   => 'Rectangle',
          members => [
            $point_def, 2,
          ]
        );

        $ffi->attach( print_rectangle => ['rectangle_t'] );

        my $rect = Rectangle->new([
          { x => 1.5,  y => 2.0  },
          { x => 3.14, y => 11.0 },
        ]);

        print_rectangle($rect);  # [[1.5 2] [3.14 11]]

        # move rectangle on the y axis
        $rect->[$_]->y( $rect->[$_]->y + 1.0 ) for 0..1;

        print_rectangle($rect);  # [[1.5 3] [3.14 12]]