From: "Mostyn Lee" <mostyn AT ibc DOT com DOT au DOT SPAM>
Newsgroups: comp.lang.c++,comp.os.msdos.djgpp
Subject: passing istringstream as istream in param
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Date: Fri, 8 Sep 2000 10:26:19 +0800
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To: djgpp AT delorie DOT com
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i used flex to generate a parser c++ class, and this class requires a
istream * as its parameter

yyFlexLexer::yyFlexLexer( istream* arg_yyin, ostream* arg_yyout )

i need to parse from a character buffer, and have created a istringstream.
the object will not accept the istringstream as a valid type parameter.
i am using visual c++ 6.0 with a GNU flex generated class


#include <iostream>
#include <string>
#include <sstream>
// ....
using namespace std;
// ....

  string constructstring = ReturnsAString();
  istringstream lexingstream(constructstring);
  lexingstream << constructstring;

   yyFlexLexer myyyFlexLexer(&lexingstream, std::cout);
// ....

gets the error :
error C2664: '__thiscall yyFlexLexer::yyFlexLexer(class istream *,class
ostream *)' : cannot convert parameter 1 from 'class
std::basic_istream<char,struct std::char_traits<char> > *' to 'class istream
*'

i have tried several things
: i have tried to declare a istream to copy the data into, but i always get
an "ambiguous symbol `istream` " error
: i have tried using various `using` and direct (std::istream) methods, but
all have errors

do I need some sort of casting?
am I #including something wrong?
why cant I just declare,
        istream streamname;