Consider the code:
考虑一下代码:
template<template<typename,typename> class Container>
class A {
template<class U, class Allocator>
void Foo(Container<U, Allocator>*, U);
};
Now I want to specialize A
in the case the Container is a map where the Value and Comparator are known, and create a definition of Foo
in this case (no specialization of Foo
). I tried this:
现在我想专门研究A,在这种情况下,Container是一个已知Value和Comparator的地图,并在这种情况下创建Foo的定义(没有Foo的专业化)。我试过这个:
template<typename V, typename Comp> template<class U, class Allocator>
void A<std::map<typename, V, Comp, typename>>::Foo(map<U, V, Comp, Allocator>*, U ) {...}
But I get the compiling error:C3200: 'std::map<int,V,Comp,int>' : invalid template argument for template parameter 'Container', expected a class parameter.
但是我得到了编译错误:C3200:'std :: map
I have looked online and only found similar issues, but I couldn't find a way to specify only partial template parameter list of a template template. Is there a way to do it?
我已经在线查找并且只发现了类似的问题,但我找不到一种方法来仅指定模板模板的部分模板参数列表。有办法吗?
EDIT: The only problem is when giving a template class partial specialization is to make it behave as a template with the remaining parameters. Here it's an attempt to think of a map<*,Known1,Known2,*>
as a template of only 2 arguments (which can realy be used as the template template parameter of A
) .
编辑:唯一的问题是,给模板类部分特化是使其表现为具有其余参数的模板。这里尝试将地图<*,Known1,Known2,*>视为仅有2个参数的模板(可以真正用作A的模板模板参数)。
EDIT 2: The compiler I have to use is GCC 4.1.2 that has no support for template aliasing, which, as I understood, is a solution.
编辑2:我必须使用的编译器是GCC 4.1.2,它不支持模板别名,据我所知,这是一种解决方案。
1 个解决方案
#1
3
The problem is that A
takes a template template parameter that takes two types:
问题是A采用模板模板参数,它有两种类型:
template<template<typename,typename> Container>
class A {
But std::map
doesn't take two types. It takes four:
但是std :: map不需要两种类型。需要四个:
template<
class Key,
class T,
class Compare = std::less<Key>,
class Allocator = std::allocator<std::pair<const Key, T> >
> class map;
So that's one problem. You will have to generalize your template to the following (also note the missing class
keyword):
这是一个问题。您必须将模板概括为以下内容(还要注意缺少的类关键字):
template <template <typename...> class Container>
class A { ... };
But even with that, at most you could completely explicitly specialize a member function, you can't partially specialize it:
但即便如此,最多你可以完全明确地专门化一个成员函数,你不能部分专门化它:
template <>
template <>
void A<std::map>::Foo<>(std::map<U, V>*, U) { ... }
#1
3
The problem is that A
takes a template template parameter that takes two types:
问题是A采用模板模板参数,它有两种类型:
template<template<typename,typename> Container>
class A {
But std::map
doesn't take two types. It takes four:
但是std :: map不需要两种类型。需要四个:
template<
class Key,
class T,
class Compare = std::less<Key>,
class Allocator = std::allocator<std::pair<const Key, T> >
> class map;
So that's one problem. You will have to generalize your template to the following (also note the missing class
keyword):
这是一个问题。您必须将模板概括为以下内容(还要注意缺少的类关键字):
template <template <typename...> class Container>
class A { ... };
But even with that, at most you could completely explicitly specialize a member function, you can't partially specialize it:
但即便如此,最多你可以完全明确地专门化一个成员函数,你不能部分专门化它:
template <>
template <>
void A<std::map>::Foo<>(std::map<U, V>*, U) { ... }