Re: overloading with templates

From:
=?ISO-8859-1?Q?=D6=F6_Tiib?= <ootiib@hot.ee>
Newsgroups:
comp.lang.c++
Date:
Fri, 20 Aug 2010 01:14:10 -0700 (PDT)
Message-ID:
<8c8ff196-a118-4cae-b599-68d61127136a@t20g2000yqa.googlegroups.com>
On 20 aug, 11:02, Sensei <sensei...@apple.me.com> wrote:

"Ron AF Greve" <me@localhost> wrote:

Hi,

As the others said post code:


Ok, thanks to all of you, I'll post an exhaustive code then!

After fixing my code, now I am trying to do the other way round: from a
string to either a type or a vector. However, I cannot compile my code,
due to a "call to fromString(std::string &) is ambiguous":

#include <vector>
#include <string>
#include <iostream>

using namespace std;

template<class T> T fromString(string src)
{
   return "output T" << endl;

};

template<class T> vector<T> fromString(string src)
{
   return "output vector of T" << endl;

};

int main()
{
   string s("3.1415");
   cout << fromString<double>( s ) << endl;

   return 0;

}

I hope my code is ok. I paid attention to specializing the call to the
template function, but as I said, I am learning C++ so I am still making
mistakes!

If I specialize the call with an explicit reference to a double output,
why is it still ambiguous?

Thanks & cheers!

--
Sensei@iPhone


You need to go few books back and discover C++ without templates
first. Your posted code is buggy because of something like that:

 #include <vector>
 #include <string>
 #include <iostream>

 using namespace std;

 double fromString( string src )
 {
    return 0.1;
 };

 vector<double> fromString( string src )
 {
    return vector<double>();
 };

 int main()
 {
    string s("3.1415");
    cout << fromString( s ) << endl;

    return 0;
 }

What is ambiguous?

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