模板模板参数与容器和默认分配器:我可以让我的声明更紧凑吗? [英] template template parameters with container and default allocator: can I make my declaration more compact?
问题描述
我在看这个有趣的线索:
http://stackoverflow.com/a/16596463/2436175
我的具体情况涉及使用cv :: Point_和cv :: Rect_从opencv的std容器声明模板函数。
我想要模板:
- 我将使用的std容器类型
- 基本数据类型完成cv :: Point_和cv :: Rect _ 的定义
我最后用下面的声明:
template< typename T,template< typename,typename> class Container_t>
void CreateRects(const Container_t< cv :: Point_< T>,std :: allocator< cv :: Point_&T>>>& points,
const T value,
Container_t< cv :: Rect_< T>,std :: allocator< cv :: Rect_< T>>>& rects){
}
void dummy(){
const std :: vector< cv :: Point_< double> >点数;
std :: vector< cv :: Rect_< double> >矩形
CreateRects(points,5.0,rects);
}
(我也看到我也可以使用
CreateRects< double>(points,5,rects)
)
我想知道是否存在任何方式使我的声明更加紧凑,例如
解决方案您可以添加模板参数的描述模板参数
Container_t
到您的功能模板:模板
&
typename T,
template
<
typename U,
typename = std :: allocator< U>
>
类Container_t
>
void CreateRects
(
const Container_t< cv :: Point_< T>& points,
const T value,
Container_t< cv :: Rect_< T>& rects
)
{
}
或者您可以使用C ++ 11可变参数模板:
template
&
typename T,
template< typename ...> Container_t
>
void CreateRects
(
const Container_t< cv :: Point_< T>& points,
const T value,
Container_t< cv :: Rect_& T>& rects
)
{
}
I was looking at this interesting thread: http://stackoverflow.com/a/16596463/2436175
My specific case concerns declaring a templated function using a std container of cv::Point_ and cv::Rect_ from opencv. I want to template against:
- the type of std container I will use
- the basic data types to complete the definition of cv::Point_ and cv::Rect_
I ended up with the following declaration:
template <typename T, template <typename, typename> class Container_t>
void CreateRects(const Container_t<cv::Point_<T>,std::allocator<cv::Point_<T> > >& points,
const T value,
Container_t<cv::Rect_<T>,std::allocator<cv::Rect_<T> > >& rects) {
}
which compiles fine with this:
void dummy() {
const std::vector<cv::Point_<double> > points;
std::vector<cv::Rect_<double> > rects;
CreateRects(points,5.0,rects);
}
(I have also seen that I can also use, for example, CreateRects<double>(points,5,rects)
)
I was wondering if there existed any way to make my declaration more compact, e.g. without the need to specify 2 times the default allocator.
You can add description for template parameters of template template parameter Container_t
to your function template:
template
<
typename T,
template
<
typename U,
typename = std::allocator<U>
>
class Container_t
>
void CreateRects
(
const Container_t<cv::Point_<T> >& points,
const T value,
Container_t<cv::Rect_<T> >& rects
)
{
}
Or you can use C++11 variadic templates:
template
<
typename T,
template <typename...> class Container_t
>
void CreateRects
(
const Container_t<cv::Point_<T>>& points,
const T value,
Container_t<cv::Rect_<T>>& rects
)
{
}
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