xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.drop.while/general.pass.cpp (revision 594fa1474f0c96da864257c0cda31b9b8381cd15)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 
11 // Some basic examples of how drop_while_view might be used in the wild. This is a general
12 // collection of sample algorithms and functions that try to mock general usage of
13 // this view.
14 
15 #include <algorithm>
16 #include <cassert>
17 #include <ranges>
18 #include <string_view>
19 
main(int,char **)20 int main(int, char**) {
21   using namespace std::string_view_literals;
22   std::string_view source = "  \t   \t   \t   hello there"sv;
23   auto is_invisible       = [](const auto x) { return x == ' ' || x == '\t'; };
24   auto skip_ws            = std::views::drop_while(source, is_invisible);
25   assert(std::ranges::equal(skip_ws, "hello there"sv));
26 
27   return 0;
28 }
29