VC++ 7.1 compiler bug with default parameters

  • Thread starter Thread starter John Madsen
  • Start date Start date
J

John Madsen

This bug is easier to just show than to explain I think...

namespace M {
template <class T> struct A {
void f(int a = T::foo()) { } // line 5
};
}

namespace N {
struct B {
static int foo() { return 5; }
};
}

int main() {
M::A<N::B> x;
x.f();
}

VC++ 7.1 (13.10.3077) produces the following diagnostic:
test.cpp(5) : error C2653: 'B' : is not a class or namespace name
test.cpp(5) : error C3861: 'foo': identifier not found, even with
argument-dependent lookup

Taking B out of namespace N makes it work, as does eliminating the
default parameter and providing an overload of A::f with no parameters
(which can serve a general workaround -- although it would be annoying
for constructors).

Both gcc 3.2 and Comeau 4.3.1 compile this code with no problem.

John
 
Looks like this is a known issue that will be addressed in the next version.
This workaround may be more acceptable:

namespace N {
struct B {
static int foo() { return 5; }
};
}

using namespace N;
namespace M {
template <class T> struct A {
int f(int a = T::foo()) { return a; } // line 5
};
}


int main() {
M::A<N::B> x;
std::cout << x.f();
}

Adam Mitz
Microsoft
--------------------
From: (e-mail address removed) (John Madsen)
Newsgroups: microsoft.public.dotnet.languages.vc
Subject: VC++ 7.1 compiler bug with default parameters
Date: 23 Jul 2003 17:08:17 -0700
Organization: http://groups.google.com/
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This bug is easier to just show than to explain I think...

namespace M {
template <class T> struct A {
void f(int a = T::foo()) { } // line 5
};
}

namespace N {
struct B {
static int foo() { return 5; }
};
}

int main() {
M::A<N::B> x;
x.f();
}

VC++ 7.1 (13.10.3077) produces the following diagnostic:
test.cpp(5) : error C2653: 'B' : is not a class or namespace name
test.cpp(5) : error C3861: 'foo': identifier not found, even with
argument-dependent lookup

Taking B out of namespace N makes it work, as does eliminating the
default parameter and providing an overload of A::f with no parameters
(which can serve a general workaround -- although it would be annoying
for constructors).

Both gcc 3.2 and Comeau 4.3.1 compile this code with no problem.

John
Click to expand...


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