[Boost-users] [enable_if] Compiler workaround for constructor overloads

From: Michael Marcin (mmarcin_at_[hidden])
Date: 2006-11-22 15:17:55

Hello I'm working with a Codewarrior compiler (Nokia Codewarrior C/C++ 
Compiler for Windows/x86 version 3.2.3 build 451).

The following test code finds the proper overload for MSVC 2005 and doesn't 
for the Codewarrior compiler but only with the = syntax.  Does anyone have 
any idea how to make "c" find its overload as well?  It would make the 
client code a lot cleaner to read/write.

#include <boost/type_traits/is_integral.hpp>
#include <boost/utility/enable_if.hpp>

struct tester
{
 int value;

 tester( float f )
  : value((int)f)
 {
 }

 tester( double d )
  : value((int)d)
 {
 }

 template< typename T >
 tester( T val, typename boost::enable_if< boost::is_integral<T> >::type* = 
0 )
  : value(val)
 {
  zzz
 }
};

void main()
{
 tester a = 1.f; // works (chooses float overload)
 tester b(1); // works (i.e. error on zzz)
 tester c = 1; // works on vc2005 (i.e. error on zzz)
     // fails on cw (ambiguous overload looking at float and double)
}