D has complete (IMHO) compiler support for calling C functions (using
extern(C)). But there is a lack of library support. Microsoft .NET
Framework has such support, but it's poor (see previous thread about
CWrap in digitalmars.D NG).
Once original function is properly described in IDL, CWrap gives the
fallowing advantages:
* [memory-corruption-safe] User works with arrays, not separate pointers
and lengths.
* [memory-leak-safe] Original function allocated memory will be freed on
any failure (NOTE: see "Original function restrictions" in documentation).
* [fail-safe] An exception will be thrown if original function fails.
* [usability] Much easier to work with arrays/preferred string types (it
converts UTF-8/16/32 back and forth, see docs).
* [speed] No unnecessary GC (or other) allocations/copying/reading.
* [garbage-free] Look at, e.g. std.file - it leaves lots of garbage
because of calling native platform functions. Generated wrappers don't
even allocate GC memory (except for output parameters when user do want
get GC allocated buffers).
Sources: https://bitbucket.org/denis_sh/cwrap
Docs (incomplete): http://deoma-cmd.ru/d/docs/src/cwrap.html
Phobos is needed.
Besides Phobos, the only file needed for generating: cwrap.d
The only file needed for generated wrappers to work: internal/cwraprt.d
Library state: almost every internal function is unittested, generated
wrappers pass rather complicated test-suit in internal/cwrapunittests.d
"Examples" is the most informative section of the documentation. Other
examples:
1. Original functions, all in one file:
https://bitbucket.org/denis_sh/cwrap/src/tip/examples/c.d
https://bitbucket.org/denis_sh/cwrap/src/tip/internal/cwrapunittests.d
2. Generated wrappers:
https://bitbucket.org/denis_sh/cwrap/src/tip/out
NOTE1: You need dmd 2.058 to generate wrappers at CT.
NOTE2: You can change `enum data` to `auto data` in examples/c.d, this
will reduce compilation time.
Previous thread about CWrap in digitalmars.D NG:
http://www.digitalmars.com/d/archives/digitalmars/D/Higher_abstraction_level_for_calling_C_functions_156633.html
