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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /dom/canvas/TupleUtils.h | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'dom/canvas/TupleUtils.h')
-rw-r--r-- | dom/canvas/TupleUtils.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/dom/canvas/TupleUtils.h b/dom/canvas/TupleUtils.h new file mode 100644 index 0000000000..f5fe19378b --- /dev/null +++ b/dom/canvas/TupleUtils.h @@ -0,0 +1,64 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef DOM_CANVAS_TUPLE_UTILS_H +#define DOM_CANVAS_TUPLE_UTILS_H + +#include <tuple> + +namespace mozilla { + +// - +// ToTupleOfConstRefs + +template <class T> +constexpr const auto& ToConstRef1(T& ret) { + return ret; +} + +template <class Tup, size_t... Ids> +constexpr auto ToTupleOfConstRefsN(const Tup& tup, + const std::index_sequence<Ids...>&) { + return std::tie(ToConstRef1(std::get<Ids>(tup))...); +} + +template <class... Args, size_t... Ids, class Tup = std::tuple<Args...>> +constexpr auto ToTupleOfConstRefs(const Tup& tup) { + return ToTupleOfConstRefsN( + tup, std::make_index_sequence<std::tuple_size_v<Tup>>()); +} + +// - +// MapTuple + +template <class Tup, class Callable, size_t... Ids> +constexpr auto MapTupleN(Tup&& tup, Callable&& fn, + const std::index_sequence<Ids...>&) { + return std::make_tuple(fn(std::get<Ids>(tup))...); +} + +/// Callable::operator()(T) cannot return void or you will get weird errors. +template <class... Args, class Callable, class Tup = std::tuple<Args...>> +constexpr auto MapTuple(Tup&& t, Callable&& fn) { + using Tup2 = typename std::remove_reference<Tup>::type; + return MapTupleN(t, fn, std::make_index_sequence<std::tuple_size_v<Tup2>>()); +} + +// - + +template <class Tup> +struct SizeofTupleArgs; + +// c++17 fold expressions make this easy, once we pull out the Args parameter +// pack by constraining the default template: +template <class... Args> +struct SizeofTupleArgs<std::tuple<Args...>> + : std::integral_constant<size_t, (... + sizeof(Args))> {}; + +static_assert(SizeofTupleArgs<std::tuple<size_t, char, char, char>>::value == + sizeof(size_t) + 3); + +} // namespace mozilla + +#endif // DOM_CANVAS_TUPLE_UTILS_H |