From Jason Turner

[pointer.traits]

C++14 → C++17 3.6 KB 48 lines
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Archived: C++14 | C++17
Markdown: C++14 | C++17
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  1. tmp/tmpsitxyf54/{from.md → to.md} +24 -20
tmp/tmpsitxyf54/{from.md → to.md} RENAMED
@@ -4,23 +4,23 @@ The class template `pointer_traits` supplies a uniform interface to
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  certain attributes of pointer-like types.
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  ``` cpp
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  namespace std {
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  template <class Ptr> struct pointer_traits {
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- typedef Ptr pointer;
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- typedef see below element_type;
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- typedef see below difference_type;
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  template <class U> using rebind = see below;
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  static pointer pointer_to(see below r);
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  };
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  template <class T> struct pointer_traits<T*> {
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- typedef T* pointer;
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- typedef T element_type;
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- typedef ptrdiff_t difference_type;
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  template <class U> using rebind = U*;
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  static pointer pointer_to(see below r) noexcept;
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  };
@@ -28,45 +28,49 @@ namespace std {
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  ```
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  #### Pointer traits member types <a id="pointer.traits.types">[[pointer.traits.types]]</a>
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  ``` cpp
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- typedef see below element_type;
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  ```
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- *Type:* `Ptr::element_type` if such a type exists; otherwise, `T` if
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- `Ptr` is a class template instantiation of the form
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- `SomePointer<T, Args>`, where `Args` is zero or more type arguments;
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- otherwise, the specialization is ill-formed.
 
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  ``` cpp
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- typedef see below difference_type;
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  ```
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- *Type:* `Ptr::difference_type` if such a type exists; otherwise,
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- `std::ptrdiff_t`.
 
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  ``` cpp
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  template <class U> using rebind = see below;
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  ```
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- *Alias template:* `Ptr::rebind<U>` if such a type exists; otherwise,
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- `SomePointer<U, Args>` if `Ptr` is a class template instantiation of the
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- form `SomePointer<T, Args>`, where `Args` is zero or more type
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- arguments; otherwise, the instantiation of `rebind` is ill-formed.
 
 
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  #### Pointer traits member functions <a id="pointer.traits.functions">[[pointer.traits.functions]]</a>
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  ``` cpp
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  static pointer pointer_traits::pointer_to(see below r);
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  static pointer pointer_traits<T*>::pointer_to(see below r) noexcept;
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  ```
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- If `element_type` is (possibly cv-qualified) `void`, the type of `r` is
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  unspecified; otherwise, it is `element_type&`.
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  *Returns:* The first member function returns a pointer to `r` obtained
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  by calling `Ptr::pointer_to(r)` through which indirection is valid; an
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  instantiation of this function is ill-formed if `Ptr` does not have a
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  matching `pointer_to` static member function. The second member function
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- returns `std::addressof(r)`.
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  certain attributes of pointer-like types.
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  ``` cpp
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  namespace std {
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  template <class Ptr> struct pointer_traits {
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+ using pointer = Ptr;
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+ using element_type = see below;
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+ using difference_type = see below;
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  template <class U> using rebind = see below;
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  static pointer pointer_to(see below r);
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  };
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  template <class T> struct pointer_traits<T*> {
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+ using pointer = T*;
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+ using element_type = T;
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+ using difference_type = ptrdiff_t;
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  template <class U> using rebind = U*;
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  static pointer pointer_to(see below r) noexcept;
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  };
 
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  ```
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  #### Pointer traits member types <a id="pointer.traits.types">[[pointer.traits.types]]</a>
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  ``` cpp
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+ using element_type = see below;
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  ```
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+ *Type:* `Ptr::element_type` if the *qualified-id* `Ptr::element_type` is
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+ valid and denotes a type ([[temp.deduct]]); otherwise, `T` if `Ptr` is
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+ a class template instantiation of the form `SomePointer<T, Args>`, where
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+ `Args` is zero or more type arguments; otherwise, the specialization is
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+ ill-formed.
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  ``` cpp
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+ using difference_type = see below;
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  ```
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+ *Type:* `Ptr::difference_type` if the *qualified-id*
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+ `Ptr::difference_type` is valid and denotes a type ([[temp.deduct]]);
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+ otherwise, `ptrdiff_t`.
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  ``` cpp
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  template <class U> using rebind = see below;
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  ```
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+ *Alias template:* `Ptr::rebind<U>` if the *qualified-id*
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+ `Ptr::rebind<U>` is valid and denotes a type ([[temp.deduct]]);
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+ otherwise, `SomePointer<U, Args>` if `Ptr` is a class template
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+ instantiation of the form `SomePointer<T, Args>`, where `Args` is zero
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+ or more type arguments; otherwise, the instantiation of `rebind` is
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+ ill-formed.
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  #### Pointer traits member functions <a id="pointer.traits.functions">[[pointer.traits.functions]]</a>
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  ``` cpp
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  static pointer pointer_traits::pointer_to(see below r);
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  static pointer pointer_traits<T*>::pointer_to(see below r) noexcept;
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  ```
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+ *Remarks:* If `element_type` is cv `void`, the type of `r` is
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  unspecified; otherwise, it is `element_type&`.
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  *Returns:* The first member function returns a pointer to `r` obtained
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  by calling `Ptr::pointer_to(r)` through which indirection is valid; an
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  instantiation of this function is ill-formed if `Ptr` does not have a
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  matching `pointer_to` static member function. The second member function
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+ returns `addressof(r)`.
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