D - C(/C++) interoperability
- "Matthew Wilson" <dmd synesis.com.au> Mar 20 2003
- "Walter" <walter digitalmars.com> Mar 20 2003
- "Matthew Wilson" <dmd synesis.com.au> Mar 21 2003
- "Walter" <walter digitalmars.com> Mar 21 2003
- Russ Lewis <spamhole-2001-07-16 deming-os.org> Mar 21 2003
- Ilya Minkov <midiclub 8ung.at> Mar 21 2003
I know that one can declare something extern (C) to use a function written in C from within D source. I want to create a C function that can return (D-type) char[]. Is this possible? I presume it'll require some C include files for the D infrastructure ... All help gratefully received. Matthew
Mar 20 2003
"Matthew Wilson" <dmd synesis.com.au> wrote in message news:b5e2ar$2l47$1 digitaldaemon.com...I know that one can declare something extern (C) to use a function written in C from within D source. I want to create a C function that can return (D-type) char[]. Is this possible? I presume it'll require some C include files for the D infrastructure ... All help gratefully received.
All you need to do is return a struct that looks like this: struct Array { int length; void *data; };
Mar 20 2003
allocated from where? "Walter" <walter digitalmars.com> wrote in message news:b5eb13$2tuh$1 digitaldaemon.com..."Matthew Wilson" <dmd synesis.com.au> wrote in message news:b5e2ar$2l47$1 digitaldaemon.com...I know that one can declare something extern (C) to use a function
in C from within D source. I want to create a C function that can return (D-type) char[]. Is this possible? I presume it'll require some C include files for the D infrastructure ... All help gratefully received.
All you need to do is return a struct that looks like this: struct Array { int length; void *data; };
Mar 21 2003
"Walter" <walter digitalmars.com> It's returned in the register pair EDX:EAX, so it doesn't matter where it is allocated. "Matthew Wilson" <dmd synesis.com.au> wrote in message news:b5ehu2$3kd$1 digitaldaemon.com...allocated from where? "Walter" <walter digitalmars.com> wrote in message news:b5eb13$2tuh$1 digitaldaemon.com..."Matthew Wilson" <dmd synesis.com.au> wrote in message news:b5e2ar$2l47$1 digitaldaemon.com...I know that one can declare something extern (C) to use a function
in C from within D source. I want to create a C function that can
(D-type) char[]. Is this possible? I presume it'll require some C include files for the
infrastructure ... All help gratefully received.
All you need to do is return a struct that looks like this: struct Array { int length; void *data; };
Mar 21 2003
Walter wrote:"Matthew Wilson" <dmd synesis.com.au> wrote in message news:b5e2ar$2l47$1 digitaldaemon.com...I know that one can declare something extern (C) to use a function written in C from within D source. I want to create a C function that can return (D-type) char[]. Is this possible? I presume it'll require some C include files for the D infrastructure ... All help gratefully received.
All you need to do is return a struct that looks like this: struct Array { int length; void *data; };
Walter, I know that yo ucan do this, but it is a very bad idea! This struct is not defined in the spec, so it totally depends on the implementation of the compiler. We need to define a standard way to do this, even if the standard is simply this. -- The Villagers are Online! villagersonline.com .[ (the fox.(quick,brown)) jumped.over(the dog.lazy) ] .[ (a version.of(English).(precise.more)) is(possible) ] ?[ you want.to(help(develop(it))) ]
Mar 21 2003
Russ Lewis wrote:Walter, I know that yo ucan do this, but it is a very bad idea! This struct is not defined in the spec, so it totally depends on the implementation of the compiler. We need to define a standard way to do this, even if the standard is simply this.
It's the same with "%.*s" printf format - it relies upon this struct just as well. So it can be considered as a part of specification. It is even mentioned under "memory layout" in the spec. -i.
Mar 21 2003