record_layout_1

 record_layout_1($ffi, $type => $name, ... );
 record_layout_1(\@ffi_args, $type => $name, ... );
 record_layout_1($type => $name, ... );

Define the layout of the record. You may optionally provide an instance of FFI::Platypus as the first argument in order to use its type aliases. Alternatively you may provide constructor arguments that will be passed to the internal platypus instance. Thus this is the same:

 my $ffi = FFI::Platypus->new( lang => 'Rust', api => 1 );
 record_layout_1( $ffi, ... );
 # same as:
 record_layout_1( [ lang => 'Rust' ], ... );

and this is the same:

 my $ffi = FFI::Platypus->new( api => 1 );
 record_layout_1( $ffi, ... );
 # same as:
 record_layout_1( ... );

Then you provide members as type/name pairs.

For each member you declare, "record_layout_1" will create an accessor which can be used to read and write its value. For example imagine a class "Foo":

 package Foo;
 
 use FFI::Platypus::Record;
 
 record_layout_1(
   int          => 'bar',  #  int bar;
   'string(10)' => 'baz',  #  char baz[10];
 );

You can get and set its fields with like named "bar" and "baz" accessors:

 my $foo = Foo->new;
 
 $foo->bar(22);
 my $value = $foo->bar;
 
 $foo->baz("grimlock\0\0"); # should be 10 characters long
 my $string_value = $foo->baz; # includes the trailing \0\0

You can also pass initial values in to the constructor, either passing as a list of key value pairs or by passing a hash reference:

 $foo = Foo->new(
   bar => 22,
   baz => "grimlock\0\0",
 );
 
 # same as:
 
 $foo = Foo->new( {
   bar => 22,
   baz => "grimlock\0\0",
 } );

If there are members of a record that you need to account for in terms of size and alignment, but do not want to have an accessor for, you can use ":" as a place holder for its name:

 record_layout_1(
   'int'        => ':',
   'string(10)' => 'baz',
 );

strings

So far I've shown fixed length strings. These are declared with the word "string" followed by the length of the string in parentheticals. Fixed length strings are included inside the record itself and do not need to be allocated or deallocated separately from the record. Variable length strings must be allocated on the heap, and thus require a sense of "ownership", that is whomever allocates variable length strings should be responsible for also free'ing them. To handle this, you can add a "ro" or "rw" trait to a string field. The default is "ro", means that you can get, but not set its value:

 package Foo;
 
 record_layout_1(
   'string ro' => 'bar',  # same type as 'string' and 'string_ro'
 );
 
 package main;
 
 my $foo = Foo->new;
 
 my $string = $foo->bar;  # GOOD
 $foo->bar("starscream"); # BAD

If you specify a field is "rw", then you can set its value:

 package Foo;
 
 record_layout_1(
   'string rw' => 'bar',  # same type as 'string_rw'
 );
 
 package main;
 
 my $foo = Foo->new;
 
 my $string = $foo->bar;  # GOOD
 $foo->bar("starscream"); # GOOD

Any string value that is pointed to by the record will be free'd when it falls out of scope, so you must be very careful that any "string rw" fields are not set or modified by C code. You should also take care not to copy any record that has a "rw" string in it because its values will be free'd twice!

 use Clone qw( clone );
 
 my $foo2 = clone $foo;  # BAD  bar will be free'd twice

arrays

Arrays of integer, floating points and opaque pointers are supported.

 package Foo;
 
 record_layout_1(
   'int[10]' => 'bar',
 );
 
 my $foo = Foo->new;
 
 $foo->bar([1,2,3,4,5,6,7,8,9,10]); # sets the values for the array
 my $list = $foo->bar;  # returns a list reference
 
 $foo->bar(5, -6); # sets the 5th element in the array to -6
 my $item = $foo->bar(5); gets the 5th element in the array

record_layout

 record_layout($ffi, $type => $name, ... );
 record_layout(\@ffi_args, $type => $name, ... );
 record_layout($type => $name, ... );

This function works like "record_layout" except that "api => 0" is used instead of "api => 1". All new code should use "record_layout_1" instead.