=head1 NAME

XS::STL::ErrorCode - Perl binding for C++ STL's std::error_code.



=head1 SYNOPSIS

    my $err = SomeFramework->some_method();
    if ($err) {
        say $err;
        say $err->value;
        say $err->category->name;
        say $err->message;
    }



=head1 DESCRIPTION

This binding is intended for use from XS modules that returns errors as C<std::error_code> objects to perl.
It provides them with typemap for C<std::error_code> and Perl interface.

This module comes with interface to all defined error codes and categories in STL.
Usually XS modules make use of both STL's categories and custom categories, see certain module docs for details.



=head1 API

=head4 new($code, $category)

Creates error code object from code and category. Normally you should not create these objects from perl.
  
    
=head4 value()

Returns error code value (integer)


=head4 category()

Returns error code category as L<XS::STL::ErrorCategory> object


=head4 message()

Returns error message


=head4 operator bool

Returns true if object contains error


=head4 operator ""

Stringifies to something like "<message>(<code>:<category>)", for example "Permission denied (13:generic)"


=head4 operator ==, eq

If second operand is a C<XS::STL::ErrorCode> object, compares code values and categories.

If second operand is a number, then compares only code value with that number.

If second operand is something else, return false



=head1 List of STL's error codes and categories

Categories (C<XS::STL::ErrorCategory> objects):

=over

=item XS::STL::generic_category

=item XS::STL::system_category

=item XS::STL::future_category

=back

Error code constants are C<XS::STL::ErrorCode> objects, not just code values. So that

    if ($err == XS::STL::errc::address_family_not_supported)
    
compares both code value and category.

=over

=item XS::STL::errc::*

    XS::STL::errc::address_family_not_supported
    XS::STL::errc::address_in_use
    ...
    
See C++ C<std::errc> docs for full list and explanation

Please note, some of values might be not available, if the C++ compiler does not
export them (e.g. C<no_message> on gcc/mingw on Windows).

=item XS::STL::future_errc::*

=back



=head1 AUTHOR

Pronin Oleg <syber@crazypanda.ru>, Crazy Panda LTD

=head1 LICENSE

You may distribute this code under the same terms as Perl itself.

=cut

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