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Newsgroups: comp.lang.ada
Date: Wed, 4 Jul 2018 04:23:22 -0700 (PDT)
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Subject: Re: Interface Ada string with C++ std::string
From: Lucretia <laguest9000@googlemail.com>
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Xref: reader02.eternal-september.org comp.lang.ada:53572
Date: 2018-07-04T04:23:22-07:00
List-Id: <comp.lang.ada>

On Wednesday, 4 July 2018 04:33:59 UTC+1, Roger  wrote:
> On Wednesday, July 4, 2018 at 2:56:15 AM UTC+10, Lucretia wrote:
> > On Tuesday, 3 July 2018 13:59:56 UTC+1, Roger  wrote:
> > > I am need to interface an Ada procedure to a C++ function that takes a  std::string as an input parameter.
> > > Can someone advise me how to do this?
> > 
> > See https://github.com/Lucretia/test_binding
> 
> Thanks for this, it looks promising.
> I have cloned test_binding, built and run it and am now using it as a basis for my own situation.

All you probably need is a C function which returns the string c_str() to Ada which Ada can then use, wrap that in Ada. Just define a private type for the string class which is an address and pass that to the C function.

package CPP_Strings is
   type CPP_String is private;

   function Get (S : in CPP_String) return String; -- Wrap the C->Ada stuff inside here.
private
   type CPP_String is System.Address;
end CPP_Strings;