模板类中的Cython C ++静态方法 [英] Cython C++ static methods in a template class

问题描述

我在C ++中有一个带有静态方法的模板类。看起来或多或少是这样的：

I have a template class in C++ that has a static method. It looks more or less like this:

template<typename T>
class Foo {
    static std::shared_ptr<Foo<T>> doSth();
}

因此在C ++中，您会这样称呼： Foo< ; Int> :: doSth（）; 。但是，在Cython中，调用静态方法的方法是使用类名作为命名空间：

so in C++ you would call it like: Foo<Int>::doSth();. In Cython however, the way to call static methods is by using the classname as a namespace:

cdef extern from "Bar.h" namespace "Bar":
    shared_ptr[Bar] doSth()  # assuming shared_ptr is already declared

但这没有模板的概念。显然，仅将 Foo< T> 作为命名空间传递是行不通的，因为它会转换为 Foo< T> :: doStr（）

but this has no notion of templates. Obviously, simply passing Foo<T> as a namespace doesn't work, because it translates to Foo<T>::doStr() in C++, no concrete type is substituted for T.

你会怎么做？在Cython中这样做吗？有办法还是解决方法？

How would you do that in Cython? Is there a way, or a workaround?

推荐答案

注意：当时的答案是正确的它已经写过（并且仍然可以使用），但是您现在应该使用 @Robertwb对此问题的答案来正确执行此操作。

Note: This answer was right at the time it was written (and does still work) but you should now use @Robertwb's answer to this question instead to do this properly.

我认为您不能直接在Cython中进行操作。您可以为普通的（非静态方法）c ++模板函数创建非常薄的包装器

I don't think you can do it directly in Cython. You could create very thin wrapper of a normal (non-static-method) c++ template function

template <typename T>
std::shared_ptr<Foo<T>> Foo_T_doSth<T>() {
   return Foo<T>::doSth();
}

，然后将此方法包装在Cython中

and then wrap this method in Cython

cdef extern from "..."
    shared_ptr[T] Foo_T_doSth[T]()

---

顺便说一句，在Cython中包装静态方法的推荐方法看起来是（来自 https://groups.google.com/forum/#!topic/cython-users/xaErUq2yY0s ）

cdef extern from "...":
   cdef Foo_doSth "Foo::doSth"()  # not declared as a memeber

（通过指定要用作字符串的实际函数）。这对您没有帮助，因为它无法处理模板。可能是我在您尝试的方式上给了您错误的建议...

(by specifying the actual function to use as a string). This doesn't help you here because it doesn't cope with templates. It may have been me who mis-advised you on the way you were trying...

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