23 General utilities library [utilities]

23.15 Metaprogramming and type traits [meta]

23.15.7 Transformations between types [meta.trans]

23.15.7.4 Array modifications [meta.trans.arr]

Table 48 — Array modifications

Template	Comments
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_v<remove_extent_t<int>, int>));
assert((is_same_v<remove_extent_t<int[2]>, int>));
assert((is_same_v<remove_extent_t<int[2][3]>, int[3]>));
assert((is_same_v<remove_extent_t<int[][3]>, int[3]>));

— end example ]

[ Example:

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

— end example ]