c++ - 如何调用模板成员函数？

Question

这个问题在这里已经有了答案:

关闭 9年前。

Possible Duplicate:
C++ template member function of template class called from template function

template<class T1>
class A 
{
public:
    template<class T0>
    void foo() const {}
};

template<class T0,class T1>
void bar( const A<T1>& b )
{
    b.foo<T0>();  // This throws " expected primary-expression before ‘>’ token"
}

我可以改成

b->A<T1>::template foo<T0>();

编译得很好。不过我也可以改成

b.A<T1>::template foo<T0>();

编译也很好。嗯？

如何正确调用原始代码意义上的模板成员函数？

Answer 1

刚刚找到:

根据 C++'03 标准 14.2/4:

When the name of a member template specialization appears after . or -> in a postfix-expression, or after nested-name-specifier in a qualified-id, and the postfix-expression or qualified-id explicitly depends on a template-parameter (14.6.2), the member template name must be prefixed by the keyword template. Otherwise the name is assumed to name a non-template.

正确的代码是:

b.template foo<T0>();