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我正在阅读 stl_construct.h 中的一些源代码,在大多数情况下,它在 <> 中有一些东西,我看到一些只有“ template<> ...”的行。这是什么?

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3 回答 3

10

这意味着接下来是模板专业化

于 2012-05-21T09:13:48.020 回答
2

Guess, I completely misread the Q and answered something that was not being asked.
So here I answer the Q being asked:

It is an Explicit Specialization with an empty template argument list.

When you instantiate a template with a given set of template arguments the compiler generates a new definition based on those template arguments. But there is a facility to override this behavior of definition generation. Instead of compiler generating the definition We can specify the definition the compiler should use for a given set of template arguments. This is called explicit specialization.

The template<> prefix indicates that the following template declaration takes no template parameters.

Explicit specialization can be applied to:

  • Function or class template
  • Member function of a class template
  • Static data member of a class template
  • Member class of a class template
  • Member function template of a class template &
  • Member class template of a class template
于 2012-05-21T09:18:08.637 回答
0

这是一个模板特化,其中所有模板参数都被完全指定,并且在<>.

例如:

template<class A, class B>   // base template
struct Something
{ 
    // do something here
};

template<class A>            // specialize for B = int
struct Something<A, int>
{ 
    // do something different here
};

template<>                   // specialize both parameters
struct Something<double, int>
{ 
    // do something here too
};
于 2012-05-21T09:31:27.153 回答