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From: Chris Morley on 7 May 2008 02:43
Hi,

I found a bit of a weirdo using Intel 4.5 compiler & I've seen similar bad
stuff in VC6. I don't know if it is a language 'feature' or a bug in the
compiler's template handling - the compilers are old.

Basically I have a template function (as a member in a class) with void
return & argument. To use the function you have to explicitly tell the
compiler what type - or the compiler errors (reasonable as it can't
determine the type!). The linked program then uses the first type
encountered for all links to that function (i.e. _same_ address) regardless
of they type provided! To fix it, if I declare a return type of the template
type instead of void, it links the explicitly defined function correctly! Is
this a bug with "template<class T> void fn(void) hadnling by this compiler
or a language feature in all C++ compilers? (feels like a name
mangling/linker bug to me)

Chris

e.g.

HEADER

class foo
{
public:
void SomeFN();
template<class T> void Broken();
template<class T> T Works();

};

template<class T> void Broken()
{
assert(sizeof(double) == sizeof(T)); // some code which uses T
}

template<class T> T Works()
{
assert(sizeof(double) == sizeof(T)); // some code which uses T
return 1;
}

C++

void foo:SomeFN()
{
Broken<float>(); // ok, type is float in expanded fn
Broken<double>(); // broken, type is also float!
Works<float>(); // ok, type is float
Works<double>(); // ok, type is double
}



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