20 General utilities library [utilities]

20.10 Metaprogramming and type traits [meta]

20.10.7 Transformations between types [meta.trans]

20.10.7.4 Array modifications [meta.trans.arr]

Table 55 — Array modifications
TemplateComments
template <class T>
struct remove_extent;
If T names a type “array of U”, the member typedef type shall be U, otherwise T. [ Note: For multidimensional arrays, only the first array dimension is removed. For a type “array of const U”, the resulting type is const U.  — end note ]
template <class T>
struct remove_all_extents;
If T is “multi-dimensional array of U”, the resulting member typedef type is U, otherwise T.

[Example

// the following assertions hold:
assert((is_same<remove_extent_t<int>, int>::value));
assert((is_same<remove_extent_t<int[2]>, int>::value));
assert((is_same<remove_extent_t<int[2][3]>, int[3]>::value));
assert((is_same<remove_extent_t<int[][3]>, int[3]>::value));

 — end example ]

[Example

// the following assertions hold:
assert((is_same<remove_all_extents_t<int>, int>::value));
assert((is_same<remove_all_extents_t<int[2]>, int>::value));
assert((is_same<remove_all_extents_t<int[2][3]>, int>::value));
assert((is_same<remove_all_extents_t<int[][3]>, int>::value));

 — end example ]