cppdraft_translate/cppdraft/range/zip/transform/overview.md

[range.zip.transform.overview]

25 Ranges library [ranges]

25.7 Range adaptors [range.adaptors]

25.7.26 Zip transform view [range.zip.transform]

25.7.26.1 Overview [range.zip.transform.overview]

1

#

zip_transform_view takes an invocable object and any number of views and produces a view whose Mth element is the result of applying the invocable object to the Mth elements of all views.

2

#

The name views​::​zip_transform denotes a customization point object ([customization.point.object]).

Let F be a subexpression, and let Es... be a pack of subexpressions.

• (2.1)

  If Es is an empty pack, let FD be decay_t<decltype((F))>.

  • (2.1.1)

If move_constructible &&regular_invocable<FD&> is false, or if decay_t<invoke_result_t<FD&>> is not an object type,views​::​zip_transform(F, Es...) is ill-formed.

• (2.1.2)

Otherwise, the expression views​::​zip_transform(F, Es...) is expression-equivalent to((void)F, auto(views::empty<decay_t<invoke_result_t<FD&>>>))

• (2.2)

  Otherwise, the expression views​::​zip_transform(F, Es...) is expression-equivalent to zip_transform_view(F, Es...).

3

#

[Example 1: vector v1 = {1, 2}; vector v2 = {4, 5, 6};

for (auto i : views::zip_transform(plus(), v1, v2)) { cout << i << ' '; // prints 5 7} — end example]