模板与名字空间

[OOPhaisky]

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问题：
一个模板在名字空间中定义，[不在名字空间中进行模板特化声明，直接在名字空间外面定义模板特化]这种情况允许么？（对于非模板实体，不可以[不在名字空间中首先声明就在名字空间外面加以定义]，这个想必大家都知道）
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例子：
1.类模板：
namespace ns{
template <class T>//类模板在名字空间中定义
class foo{
public:
void test(T a){
cout << "aaaa:" << a << endl;
}
};
}
template<>//类模板显式特化，未在名字空间ns中声明
class ns::foo<int>{
public:
void dddd(){
cout << "dddd" << endl;
}
};
结果：vs2005成功，g++失败。

2.函数模板：
namespace ns{
template <class T>//函数模板在名字空间中定义
void test(T a){
cout << a << endl;
}
}
template<>//函数模板显式特化，未在名字空间ns中声明
void ns::test(int){
cout << "int" << endl;
}
结果：vs2005成功，g++失败。
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望高手解答，谢谢。

[gushenghua]

俺来说句废话，这个得查C++标准，如果标准没做说明，那么写程序得避开这个问题

[chenhu_doc]

还是按照标准写，通用！

[chenhu_doc]

相对地说....

[OOPhaisky]

标准对此有相应说明么？

[triace_zhang]

ISO/IEC 14882:1998(E) -- C++ -- Templates
14.7.3 [temp.expl.spec]

2 An explicit specialization must be declared in the namespace of which
it is a member, or, for class members, in the namespace of which the
class is a member. Such a declaration may also be a definition. If

the declaration is not a definition, the specialization may be defined
later in the namespace in which the explicit specialization was
declared, or in a namespace that encloses the one in which the
explicit specialization was declared.
6 A template explicit specialization is in the scope of the namespace in
which the template was defined. [Example:

namespace N {
template<class T> class X { /* ... */ };
template<class T> class Y { /* ... */ };

template<> class X<int> { /* ... */ }; // ok: specialization
// in same namespace
template<> class Y<double>; // forward declare intent to
// specialize for double
}

template<> class N::Y<double> { /* ... */ }; // ok: specialization
// in same namespace
--end example]