An explicit specialization shall be declared in the namespace of which the template is a member, or, for member templates, in the namespace of which the enclosing class or enclosing class template is a member.
An explicit specialization shall be declared in the namespace of which the template is a member, or, for member templates, in the namespace of which the enclosing class or enclosing class template is a member.
一个显式的特化应该声明在它所在的名域中,对于成员模板来说,应该在声明于它所嵌的类所在的名域中。