Re: Problem with function not being visible
chris@foobar.com wrote:
Guys, I have the following piece of code. Could you please help me
understand why b.ToString( ) cannot be called while b.foo( ) can?
When I compile I get (gcc, but visual studio gives the same pretty
much). Thanks
Binding a reference to non-const to a temporary is prohibited.
$ g++ -Wall foo.cpp
foo.cpp: In function `int main(int, char**)':
foo.cpp:21: error: no matching function for call to `Bar::ToString()'
foo.cpp:14: note: candidates are: virtual std::string
Bar::ToString(std::string&) const
#include <stdlib.h>
#include <string>
using namespace std;
template <typename _T> class Foo {
You should avoid using names that begin with an underscore and
a capital letter. They are reserved by the implementation.
public:
virtual std::string ToString (std::string& pfx) const = 0;
std::string ToString ( ) const { return(ToString(std::string( ))); }
Are you trying to call the virtual function (declared just before) here?
You cannot bind the temporary to a refernece to non-const. You have to
change the body to be
{ std::string s; return ToString(s); }
virtual void* _foo ( ) const = 0;
void* foo( ) const { return (_foo( )); }
};
class Bar: public Foo<int> {
public:
std::string ToString (std::string& pfx) const
{ return (std::string("test")); }
void* _foo ( ) const { return(NULL); }
I've reformatted it a bit, just to fit them on a line.
};
int main (int argc, char **argv) {
Bar b;
b.foo( );
b.ToString( );
return (0);
}
V
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