c++/9489: gcc fails to find implicit conversion with template class

[jrestemeier@currantbun.com]

>Number:         9489
>Category:       c++
>Synopsis:       gcc fails to find implicit conversion with template class
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jan 28 21:46:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     jrestemeier@currantbun.com
>Release:        Apple Computer, Inc. GCC version 1151, based on gcc version 3.1 20020420 (prerelease)
>Organization:
>Environment:
MacOS/X
>Description:
template<class T> class foo {
public:
	T a, b;
	foo & operator+=(const foo &rhs) {
		a+=rhs.a;
		b+=rhs.b;
		return *this;
	}
	friend foo operator+(const foo &lhs, const foo &rhs) {
		return foo(lhs)+=rhs;
	}
};

template<class T>class bar {
public:
	T ping, pong;
	bar() {}
	bar(const foo<T> & f) {
		ping = f.a;
		pong = f.b;
	}
	bar(int a, int b) {
		ping = a;
		pong = b;
	}
	operator foo<T>() const {
		foo<T> f;
		f.a = ping;
		f.b = pong;
		return f;
	}
};

int main (int argc, const char * argv[]) {
//	foo<int> f;
	bar<int> a(1,2), b(3,4), c;
	c=a+b;
	return 0;
}

---
This fails with :
main.cpp: In function `int main(int, const char**)':
main.cpp:37: no match for `bar<int>& + bar<int>&' operator

remove the comment in front of "foo<int> f" and it compiles with just a warning about f beeing unused. 

>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: