| // Copyright 2020 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_CHARACTER_VISITOR_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_CHARACTER_VISITOR_H_ |
| |
| namespace WTF { |
| |
| // Visits the characters of a WTF::String, StringView or compatible type. |
| // |
| // Intended to be used with a generic lambda or other functor overloaded to |
| // handle either LChar* or UChar*. Reduces code duplication in many cases. |
| // The functor should return the same type in both branches. |
| // |
| // Callers should ensure that characters exist (i.e. the string is not null) |
| // first. |
| // |
| // Example: |
| // |
| // if (string.IsNull()) |
| // return false; |
| // |
| // return WTF::VisitCharacters(string, [&](const auto* chars, unsigned len) { |
| // bool contains_space = false; |
| // for (unsigned i = 0; i < len; i++) |
| // contains_space |= IsASCIISpace(chars[i]); |
| // return contains_space; |
| // }); |
| // |
| // This will instantiate the functor for both LChar (8-bit) and UChar (16-bit) |
| // automatically. |
| template <typename StringType, typename Functor> |
| decltype(auto) VisitCharacters(const StringType& string, |
| const Functor& functor) { |
| return string.Is8Bit() ? functor(string.Characters8(), string.length()) |
| : functor(string.Characters16(), string.length()); |
| } |
| |
| } // namespace WTF |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_CHARACTER_VISITOR_H_ |
