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3606 :: c2nim fails for struct with function pointer containing reference argument, how to convert manually?

• cmc (orginal) [2018-03-04T02:59:46+01:00] view original

  I would like to convert the following C++ struct to nim.

  # foo.h
  struct foo
  {
     void (*bar)(int &fuz);
  };
  Run

  c2nim does not seem to support this construct

  
  $ c2nim foo.h
  foo.h(3, 21) Error: ')' expected
  
  $ c2nim --cpp foo.h
  foo.h(3, 11) Error: identifier expected, but found '*'
  Run

  What is the correct way to convert this manually, or get reasonably close?

  This is going to be plumbing code to interface with an existing C-Style ++ codebase.

  Edit: Corrected, it's C++ not C

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• guibar (orginal) [2018-03-05T15:46:00+01:00] view original

  Isn't it

  // foo.h
  struct foo
  {
     void (*bar)(int *fuz);
  };
  Run

  or is it a c++ header ?

  Anyway, you can try something like this

  type
    foo {.importc:"foo", header:"foo.h"} = object
      bar: proc(fuz: var cint) {.cdecl.}
  Run

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• cmc (orginal) [2018-03-07T18:12:35+01:00] view original

  Yes, a C++ header, not C! Corrected.

  Compiles fine!

  I don't understand why this works though- the struct would normally go into nimcache/foo.cpp- does nim give precedence to identifiers in header files?

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• guibar (orginal) [2018-03-08T11:58:26+01:00] view original

  The struct is not defined in the generated file when you use the header pragma. It only includes the header at the top of the file.

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• cmc (orginal) [2018-03-09T16:53:00+01:00] view original

  If you include the header in the top of the generated file, wouldn't you have two structs, causing a "redefinition of 'struct Foo'" error?

  --- begin of file --- #foo.h code struct foo... # original from header

  #generated code struct foo... # generated from type statement

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